diff --git a/src/com/bytezone/diskbrowser/duplicates/DiskDetails.java b/src/com/bytezone/diskbrowser/duplicates/DiskDetails.java
index 3d6cc5a..094c40a 100644
--- a/src/com/bytezone/diskbrowser/duplicates/DiskDetails.java
+++ b/src/com/bytezone/diskbrowser/duplicates/DiskDetails.java
@@ -1,40 +1,87 @@
 package com.bytezone.diskbrowser.duplicates;
 
 import java.io.File;
+import java.util.ArrayList;
+import java.util.List;
 
 import com.bytezone.common.ComputeCRC32;
 
 public class DiskDetails
 {
   private final File file;
-  private long checksum = -1;
-  private boolean duplicate;
+  private final long checksum;
+  private final String rootName;            // full path without the root folder
+  private final String shortName;           // file name in lower case
 
-  public DiskDetails (File file)
+  private final List<DiskDetails> duplicateChecksums = new ArrayList<DiskDetails> ();
+  private final List<DiskDetails> duplicateNames = new ArrayList<DiskDetails> ();
+
+  private boolean isDuplicateName;
+  private boolean isDuplicateChecksum;
+
+  public DiskDetails (File file, String rootName, String shortName)
   {
     this.file = file;
-    duplicate = false;
+    this.rootName = rootName;
+    this.shortName = shortName;
+    checksum = ComputeCRC32.getChecksumValue (file);
   }
 
-  public boolean isDuplicate ()
+  //  public boolean isDuplicate ()
+  //  {
+  //    return duplicate;
+  //  }
+
+  public void addDuplicateChecksum (DiskDetails diskDetails)
   {
-    return duplicate;
+    if (this.checksum == diskDetails.checksum)
+    {
+      this.duplicateChecksums.add (diskDetails);
+      diskDetails.isDuplicateChecksum = true;
+    }
   }
 
-  public void setDuplicate (boolean value)
+  public void addDuplicateName (DiskDetails diskDetails)
   {
-    duplicate = value;
+    if (this.shortName.equals (diskDetails.shortName))
+    {
+      this.duplicateNames.add (diskDetails);
+      diskDetails.isDuplicateName = true;
+    }
   }
 
-  public String getAbsolutePath ()
+  public List<DiskDetails> getDuplicateChecksums ()
   {
-    return file.getAbsolutePath ();
+    return duplicateChecksums;
+  }
+
+  public List<DiskDetails> getDuplicateNames ()
+  {
+    return duplicateNames;
+  }
+
+  public boolean isDuplicateChecksum ()
+  {
+    return isDuplicateChecksum;
+  }
+
+  public boolean isDuplicateName ()
+  {
+    return isDuplicateName;
+  }
+
+  public String getRootName ()
+  {
+    return rootName;
+  }
+
+  public String getShortName ()
+  {
+    return shortName;
   }
 
   public long getChecksum ()
   {
-    if (checksum < 0)
-      checksum = ComputeCRC32.getChecksumValue (file);
     return checksum;
   }
 
@@ -47,7 +94,7 @@ public class DiskDetails
   @Override
   public String toString ()
   {
-    return String.format ("%s (%s)", file.getAbsolutePath (),
-        duplicate ? "duplicate" : "OK");
+    return String.format ("%-40s %3d %s %3d %s", rootName, duplicateChecksums.size (),
+        isDuplicateChecksum, duplicateNames.size (), isDuplicateName);
   }
 }
\ No newline at end of file
diff --git a/src/com/bytezone/diskbrowser/duplicates/DiskTableModel.java b/src/com/bytezone/diskbrowser/duplicates/DiskTableModel.java
new file mode 100644
index 0000000..013c60d
--- /dev/null
+++ b/src/com/bytezone/diskbrowser/duplicates/DiskTableModel.java
@@ -0,0 +1,118 @@
+package com.bytezone.diskbrowser.duplicates;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import javax.swing.table.AbstractTableModel;
+
+public class DiskTableModel extends AbstractTableModel
+{
+  static final String[] headers = { "Disk name", "Actual disk", "Checksum" };
+
+  Map<String, DiskDetails> fileNameMap;
+  Map<Long, DiskDetails> checkSumMap;
+  List<TableLine> lines = new ArrayList<DiskTableModel.TableLine> ();
+
+  public DiskTableModel (DuplicateHandler duplicateHandler)
+  {
+    fileNameMap = duplicateHandler.getFileNameMap ();
+    checkSumMap = duplicateHandler.getChecksumMap ();
+
+    for (String key : fileNameMap.keySet ())
+    {
+      DiskDetails original = fileNameMap.get (key);
+
+      if (false)
+      {
+        if (original.getDuplicateNames ().size () > 0)
+        {
+          lines.add (new TableLine (original));
+          for (DiskDetails duplicate : original.getDuplicateNames ())
+            lines.add (new TableLine (duplicate));
+        }
+      }
+      else
+      {
+        if (original.getDuplicateChecksums ().size () > 0)
+        {
+          lines.add (new TableLine (original));
+          for (DiskDetails duplicate : original.getDuplicateChecksums ())
+            lines.add (new TableLine (duplicate));
+        }
+        //        else if (original.isDuplicateChecksum ())
+        //        {
+        //          lines.add (new TableLine (key, original));
+        //          DiskDetails dd = checkSumMap.get (original.getChecksum ());
+        //          for (DiskDetails duplicate : dd.getDuplicateChecksums ())
+        //            lines.add (new TableLine (key, duplicate));
+        //        }
+      }
+    }
+  }
+
+  @Override
+  public String getColumnName (int column)
+  {
+    return headers[column];
+  }
+
+  @Override
+  public int getRowCount ()
+  {
+    return lines.size ();
+  }
+
+  @Override
+  public int getColumnCount ()
+  {
+    return headers.length;
+  }
+
+  @Override
+  public Class<?> getColumnClass (int columnIndex)
+  {
+    switch (columnIndex)
+    {
+      case 0:
+        return String.class;
+      case 1:
+        return String.class;
+      case 2:
+        return Long.class;
+      default:
+        return Object.class;
+    }
+  }
+
+  @Override
+  public Object getValueAt (int rowIndex, int columnIndex)
+  {
+    TableLine line = lines.get (rowIndex);
+    switch (columnIndex)
+    {
+      case 0:
+        return line.shortName;
+      case 1:
+        return line.diskDetails.getRootName ();
+      case 2:
+        return line.checksum;
+      default:
+        return "???";
+    }
+  }
+
+  class TableLine
+  {
+    String shortName;
+    DiskDetails diskDetails;
+    long checksum;
+
+    public TableLine (DiskDetails diskDetails)
+    {
+      this.shortName = diskDetails.getShortName ();
+      this.diskDetails = diskDetails;
+      this.checksum = diskDetails.getChecksum ();
+    }
+  }
+}
\ No newline at end of file
diff --git a/src/com/bytezone/diskbrowser/duplicates/DuplicateHandler.java b/src/com/bytezone/diskbrowser/duplicates/DuplicateHandler.java
index 10354cf..234d5eb 100644
--- a/src/com/bytezone/diskbrowser/duplicates/DuplicateHandler.java
+++ b/src/com/bytezone/diskbrowser/duplicates/DuplicateHandler.java
@@ -1,12 +1,10 @@
 package com.bytezone.diskbrowser.duplicates;
 
 import java.io.File;
-import java.util.*;
-import java.util.zip.CRC32;
-import java.util.zip.Checksum;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.TreeMap;
 
-import com.bytezone.diskbrowser.disk.AppleDisk;
-import com.bytezone.diskbrowser.disk.Disk;
 import com.bytezone.diskbrowser.gui.FileComparator;
 import com.bytezone.diskbrowser.utilities.Utility;
 
@@ -19,30 +17,34 @@ public class DuplicateHandler
   private final File rootFolder;
   private int totalDisks;
   private int totalFolders;
+  private final int rootFolderNameLength;
+
+  private final boolean debug = false;
 
   // total files for each suffix
   private final Map<String, Integer> typeList = new TreeMap<String, Integer> ();
 
-  // list of unique disk names -> List of File duplicates
-  final Map<String, List<DiskDetails>> duplicateDisks =
-      new TreeMap<String, List<DiskDetails>> ();
+  // list of checksum -> DiskDetails
+  final Map<Long, DiskDetails> checksumMap = new HashMap<Long, DiskDetails> ();
 
   // list of unique disk names -> File
-  private final Map<String, File> diskNames = new HashMap<String, File> ();
-
-  // list of checksum -> File
-  final Map<Long, List<File>> dosMap = new TreeMap<Long, List<File>> ();
+  private final Map<String, DiskDetails> fileNameMap =
+      new TreeMap<String, DiskDetails> ();
 
   public DuplicateHandler (File rootFolder)
   {
     this.rootFolder = rootFolder;
-
-    countDisks ();
+    rootFolderNameLength = rootFolder.getAbsolutePath ().length ();
   }
 
-  public Map<String, List<DiskDetails>> getDuplicateDisks ()
+  public Map<String, DiskDetails> getFileNameMap ()
   {
-    return duplicateDisks;
+    return fileNameMap;
+  }
+
+  public Map<Long, DiskDetails> getChecksumMap ()
+  {
+    return checksumMap;
   }
 
   void countDisks ()
@@ -62,114 +64,76 @@ public class DuplicateHandler
     System.out.printf ("%nTotal ....... %,7d%n%n", grandTotal);
   }
 
+  File getRootFolder ()
+  {
+    return rootFolder;
+  }
+
   private void traverse (File directory)
   {
     File[] files = directory.listFiles ();
+
     if (files == null || files.length == 0)
     {
       System.out.println ("Empty folder : " + directory.getAbsolutePath ());
       return;
     }
 
-    Arrays.sort (files, fileComparator);
-
-    if (false)
-      System.out.printf ("%nFolder: %s%n%n", directory.getAbsolutePath ()
-          .substring (rootFolder.getAbsolutePath ().length ()));
+    //    Arrays.sort (files, fileComparator);
 
     for (File file : files)
     {
+      String fileName = file.getName ().toLowerCase ();
+
       if (file.isDirectory ())
       {
         ++totalFolders;
         traverse (file);
       }
-      else if (Utility.validFileType (file.getName ()))
+      else if (Utility.validFileType (fileName))
       {
-        if (file.getName ().endsWith (".gz") && !file.getName ().endsWith ("dsk.gz"))
-          continue;
-
         ++totalDisks;
-
-        int pos = file.getName ().lastIndexOf ('.');
-        if (pos > 0)
-        {
-          String type = file.getName ().substring (pos + 1).toLowerCase ();
-          if (typeList.containsKey (type))
-          {
-            int t = typeList.get (type);
-            typeList.put (type, ++t);
-          }
-          else
-            typeList.put (type, 1);
-        }
-
-        if (false)
-        {
-          String name = file.getName ();
-          int nameLength = name.length ();
-          if (nameLength > MAX_NAME_WIDTH)
-            name = name.substring (0, 15) + "..."
-                + name.substring (nameLength - MAX_NAME_WIDTH + 18);
-
-          System.out.printf (FORMAT, name, file.length ());
-        }
-
-        checkDuplicates (file);
-        //        checksumDos (file);
+        incrementType (file, fileName);
+        checkDuplicates (file, fileName);
       }
     }
-
-    if (false)
-      for (String key : duplicateDisks.keySet ())
-      {
-        List<DiskDetails> diskDetailsList = duplicateDisks.get (key);
-        System.out.println (key);
-        for (DiskDetails diskDetails : diskDetailsList)
-          System.out.println (diskDetails);
-      }
   }
 
-  private void checksumDos (File file)
+  private void checkDuplicates (File file, String fileName)
   {
-    if (file.length () != 143360 || file.getAbsolutePath ().contains ("/ZDisks/"))
-      return;
+    String rootName = file.getAbsolutePath ().substring (rootFolderNameLength);
+    DiskDetails diskDetails = new DiskDetails (file, rootName, fileName);
 
-    Disk disk = new AppleDisk (file, 35, 16);
-    byte[] buffer = disk.readSector (0, 0);
-
-    Checksum checksum = new CRC32 ();
-    checksum.update (buffer, 0, buffer.length);
-    long cs = checksum.getValue ();
-    List<File> files = dosMap.get (cs);
-    if (files == null)
+    if (fileNameMap.containsKey (fileName))
     {
-      files = new ArrayList<File> ();
-      dosMap.put (cs, files);
-    }
-    files.add (file);
-  }
-
-  private void checkDuplicates (File file)
-  {
-    if (diskNames.containsKey (file.getName ()))
-    {
-      List<DiskDetails> diskList = duplicateDisks.get (file.getName ());
-      if (diskList == null)
-      {
-        diskList = new ArrayList<DiskDetails> ();
-        duplicateDisks.put (file.getName (), diskList);
-        diskList.add (new DiskDetails (diskNames.get (file.getName ())));// add original
-      }
-      diskList.add (new DiskDetails (file));                        // add the duplicate
+      DiskDetails otherDisk = fileNameMap.get (fileName);
+      otherDisk.addDuplicateName (diskDetails);
     }
     else
-      diskNames.put (file.getName (), file);
+      fileNameMap.put (fileName, diskDetails);
+
+    if (checksumMap.containsKey (diskDetails.getChecksum ()))
+    {
+      DiskDetails otherDisk = checksumMap.get (diskDetails.getChecksum ());
+      otherDisk.addDuplicateChecksum (diskDetails);
+    }
+    else
+      checksumMap.put (diskDetails.getChecksum (), diskDetails);
   }
 
-  //  public static void main (String[] args)
-  //  {
-  //    DuplicateHandler dh = new DuplicateHandler (
-  //        new File ("/Users/denismolony/Apple II stuff/AppleDisk Images II/apple disks"));
-  //  }
+  private void incrementType (File file, String fileName)
+  {
+    int pos = file.getName ().lastIndexOf ('.');
+    if (pos > 0)
+    {
+      String type = fileName.substring (pos + 1);
+      if (typeList.containsKey (type))
+      {
+        int t = typeList.get (type);
+        typeList.put (type, ++t);
+      }
+      else
+        typeList.put (type, 1);
+    }
+  }
 }
\ No newline at end of file
diff --git a/src/com/bytezone/diskbrowser/duplicates/DuplicatePanel.java b/src/com/bytezone/diskbrowser/duplicates/DuplicatePanel.java
deleted file mode 100644
index cf0d079..0000000
--- a/src/com/bytezone/diskbrowser/duplicates/DuplicatePanel.java
+++ /dev/null
@@ -1,53 +0,0 @@
-package com.bytezone.diskbrowser.duplicates;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import javax.swing.JButton;
-import javax.swing.JCheckBox;
-import javax.swing.JLabel;
-import javax.swing.JPanel;
-import javax.swing.SpringLayout;
-
-import com.bytezone.input.SpringUtilities;
-
-public class DuplicatePanel extends JPanel
-{
-  List<JCheckBox> checkBoxes = new ArrayList<JCheckBox> ();
-  List<DiskDetails> duplicateDisks;
-
-  public DuplicatePanel (List<DiskDetails> duplicateDisks, int folderNameLength,
-      List<DiskDetails> disksSelected, JButton deleteButton, JButton clearButton)
-  {
-    this.duplicateDisks = duplicateDisks;
-    setLayout (new SpringLayout ());
-    setAlignmentX (LEFT_ALIGNMENT);
-
-    int count = 0;
-    for (DiskDetails diskDetails : duplicateDisks)
-    {
-      JCheckBox checkbox = new JCheckBox ();
-      checkBoxes.add (checkbox);
-
-      checkbox.addActionListener (new CheckBoxActionListener (diskDetails, disksSelected,
-          deleteButton, clearButton));
-      add (checkbox);
-      if (++count == 1)
-        add (new JLabel ("Original disk"));
-      else
-      {
-        String text = diskDetails.isDuplicate () ? "Duplicate" : "OK";
-        add (new JLabel (text));
-      }
-      String checksum = diskDetails.isDuplicate () || count == 1 ? ""
-          : " (checksum = " + diskDetails.getChecksum () + ")";
-      add (new JLabel (
-          diskDetails.getAbsolutePath ().substring (folderNameLength) + checksum));
-    }
-
-    SpringUtilities.makeCompactGrid (this,    //
-        duplicateDisks.size (), 3,            // rows, cols
-        10, 0,                                // initX, initY
-        10, 0);                               // xPad, yPad
-  }
-}
\ No newline at end of file
diff --git a/src/com/bytezone/diskbrowser/duplicates/DuplicateWindow.java b/src/com/bytezone/diskbrowser/duplicates/DuplicateWindow.java
index 603db16..6fe2bed 100644
--- a/src/com/bytezone/diskbrowser/duplicates/DuplicateWindow.java
+++ b/src/com/bytezone/diskbrowser/duplicates/DuplicateWindow.java
@@ -1,7 +1,6 @@
 package com.bytezone.diskbrowser.duplicates;
 
 import java.awt.BorderLayout;
-import java.awt.Dimension;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
 import java.io.File;
@@ -13,7 +12,7 @@ import javax.swing.*;
 
 public class DuplicateWindow extends JFrame
 {
-  int unfinishedWorkers;
+  private final JTable table;
   int folderNameLength;
   Map<String, List<DiskDetails>> duplicateDisks;
   File rootFolder;
@@ -22,10 +21,9 @@ public class DuplicateWindow extends JFrame
   JButton buttonCancel = new JButton ("Cancel");
   JButton buttonAll = new JButton ("Select all duplicates");
   JButton buttonClear = new JButton ("Clear all");
-  JPanel mainPanel = new JPanel ();
+  //  JPanel mainPanel = new JPanel ();
 
   List<DiskDetails> disksSelected = new ArrayList<DiskDetails> ();
-  List<DuplicatePanel> duplicatePanels = new ArrayList<DuplicatePanel> ();
 
   DuplicateHandler duplicateHandler;
 
@@ -33,21 +31,18 @@ public class DuplicateWindow extends JFrame
   {
     super ("Duplicate Disk Detection - " + rootFolder.getAbsolutePath ());
 
-    duplicateHandler = new DuplicateHandler (rootFolder);
-    Map<String, List<DiskDetails>> duplicateDisks = duplicateHandler.getDuplicateDisks ();
-    for (List<DiskDetails> diskList : duplicateDisks.values ())
-      new DuplicateWorker (diskList, this).execute ();
-
-    unfinishedWorkers = duplicateDisks.size ();
     folderNameLength = rootFolder.getAbsolutePath ().length ();
 
-    mainPanel.setLayout (new BoxLayout (mainPanel, BoxLayout.PAGE_AXIS));
-
-    JScrollPane sp =
-        new JScrollPane (mainPanel, ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
+    table = new JTable ();
+    JScrollPane scrollPane =
+        new JScrollPane (table, ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
             ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
-    sp.getVerticalScrollBar ().setUnitIncrement (100);
-    add (sp, BorderLayout.CENTER);
+    table.setFillsViewportHeight (true);
+
+    //    table.setShowGrid (true);
+    //    table.setGridColor (Color.BLACK);
+
+    add (scrollPane, BorderLayout.CENTER);
 
     JPanel panel = new JPanel ();
     panel.add (buttonClear);
@@ -66,20 +61,20 @@ public class DuplicateWindow extends JFrame
       @Override
       public void actionPerformed (ActionEvent e)
       {
-        for (DuplicatePanel dp : duplicatePanels)
-        {
-          int count = 0;
-          for (JCheckBox cb : dp.checkBoxes)
-          {
-            if (count > 0 && dp.duplicateDisks.get (count).isDuplicate ())
-              if (!cb.isSelected ())
-              {
-                cb.setSelected (true);              // doesn't fire the actionListener!
-                disksSelected.add (dp.duplicateDisks.get (count));
-              }
-            ++count;
-          }
-        }
+        //        for (DuplicatePanel dp : duplicatePanels)
+        //        {
+        //          int count = 0;
+        //          for (JCheckBox cb : dp.checkBoxes)
+        //          {
+        //            if (count > 0 && dp.duplicateDisks.get (count).isDuplicate ())
+        //              if (!cb.isSelected ())
+        //              {
+        //                cb.setSelected (true);              // doesn't fire the actionListener!
+        //                disksSelected.add (dp.duplicateDisks.get (count));
+        //              }
+        //            ++count;
+        //          }
+        //        }
         buttonDelete.setEnabled (disksSelected.size () > 0);
         buttonClear.setEnabled (disksSelected.size () > 0);
       }
@@ -90,9 +85,9 @@ public class DuplicateWindow extends JFrame
       @Override
       public void actionPerformed (ActionEvent e)
       {
-        for (DuplicatePanel dp : duplicatePanels)
-          for (JCheckBox cb : dp.checkBoxes)
-            cb.setSelected (false);                 // doesn't fire the actionListener!
+        //        for (DuplicatePanel dp : duplicatePanels)
+        //          for (JCheckBox cb : dp.checkBoxes)
+        //            cb.setSelected (false);                 // doesn't fire the actionListener!
 
         disksSelected.clear ();
         buttonDelete.setEnabled (false);
@@ -116,55 +111,45 @@ public class DuplicateWindow extends JFrame
       {
         int totalDeleted = 0;
         int totalFailed = 0;
-        for (DuplicatePanel dp : duplicatePanels)
-        {
-          int count = 0;
-          for (JCheckBox cb : dp.checkBoxes)
-          {
-            if (cb.isSelected () && false)
-            {
-              DiskDetails dd = dp.duplicateDisks.get (count);
-              if (dd.delete ())
-              {
-                ++totalDeleted;
-                System.out.println ("Deleted : " + dd);
-              }
-              else
-              {
-                ++totalFailed;
-                System.out.println ("Failed  : " + dd);
-              }
-            }
-            ++count;
-          }
-        }
+
+        //        for (DuplicatePanel dp : duplicatePanels)
+        //        {
+        //          int count = 0;
+        //          for (JCheckBox cb : dp.checkBoxes)
+        //          {
+        //            if (cb.isSelected ())
+        //            {
+        //              DiskDetails dd = dp.duplicateDisks.get (count);
+        //              if (dd.delete ())
+        //              {
+        //                ++totalDeleted;
+        //                System.out.println ("Deleted : " + dd);
+        //              }
+        //              else
+        //              {
+        //                ++totalFailed;
+        //                System.out.println ("Failed  : " + dd);
+        //              }
+        //            }
+        //            ++count;
+        //          }
+        //        }
         System.out.printf ("Deleted : %d, Failed : %d%n", totalDeleted, totalFailed);
       }
     });
 
-    setSize (600, 700);
+    setSize (900, 700);
     setLocationRelativeTo (null);
     setDefaultCloseOperation (HIDE_ON_CLOSE);
+  }
+
+  public void setDuplicateHandler (DuplicateHandler duplicateHandler)
+  {
+    this.duplicateHandler = duplicateHandler;
+    table.setModel (new DiskTableModel (duplicateHandler));
+    table.getColumnModel ().getColumn (0).setPreferredWidth (250);
+    table.getColumnModel ().getColumn (1).setPreferredWidth (500);
+    table.getColumnModel ().getColumn (2).setPreferredWidth (100);
     setVisible (true);
   }
-
-  // create a DuplicatePanel based on the updated DiskDetails
-  public synchronized void addResult (List<DiskDetails> duplicateDisks)
-  {
-    // create panel and add it to the window
-    DuplicatePanel dp = new DuplicatePanel (duplicateDisks, folderNameLength,
-        disksSelected, buttonDelete, buttonClear);
-    mainPanel.add (dp);
-    duplicatePanels.add (dp);
-
-    validate ();
-
-    if (--unfinishedWorkers == 0)
-    {
-      buttonAll.setEnabled (true);
-      buttonCancel.setEnabled (true);
-    }
-    else
-      mainPanel.add (Box.createRigidArea (new Dimension (0, 20)));
-  }
-}
+}
\ No newline at end of file
diff --git a/src/com/bytezone/diskbrowser/duplicates/DuplicateWorker.java b/src/com/bytezone/diskbrowser/duplicates/DuplicateWorker.java
index c151cd8..9d4b3c4 100644
--- a/src/com/bytezone/diskbrowser/duplicates/DuplicateWorker.java
+++ b/src/com/bytezone/diskbrowser/duplicates/DuplicateWorker.java
@@ -1,18 +1,18 @@
 package com.bytezone.diskbrowser.duplicates;
 
-import java.util.List;
+import java.io.File;
 
 import javax.swing.SwingWorker;
 
-public class DuplicateWorker extends SwingWorker<List<DiskDetails>, Void>
+public class DuplicateWorker extends SwingWorker<DuplicateHandler, String>
 {
-  List<DiskDetails> duplicateDisks;
+  DuplicateHandler duplicateHandler;
   DuplicateWindow owner;
 
-  public DuplicateWorker (List<DiskDetails> duplicateDisks, DuplicateWindow owner)
+  public DuplicateWorker (File rootFolder, DuplicateWindow owner)
   {
-    this.duplicateDisks = duplicateDisks;
     this.owner = owner;
+    duplicateHandler = new DuplicateHandler (rootFolder);
   }
 
   @Override
@@ -20,7 +20,7 @@ public class DuplicateWorker extends SwingWorker<List<DiskDetails>, Void>
   {
     try
     {
-      owner.addResult (get ());
+      owner.setDuplicateHandler (get ());
     }
     catch (Exception e)
     {
@@ -29,16 +29,10 @@ public class DuplicateWorker extends SwingWorker<List<DiskDetails>, Void>
   }
 
   @Override
-  protected List<DiskDetails> doInBackground () throws Exception
+  protected DuplicateHandler doInBackground () throws Exception
   {
-    long firstChecksum = -1;
-    for (DiskDetails dd : duplicateDisks)
-    {
-      if (firstChecksum < 0)
-        firstChecksum = dd.getChecksum ();
-      else
-        dd.setDuplicate (dd.getChecksum () == firstChecksum);
-    }
-    return duplicateDisks;
+    duplicateHandler.countDisks ();
+
+    return duplicateHandler;
   }
 }
\ No newline at end of file
diff --git a/src/com/bytezone/diskbrowser/gui/DuplicateAction.java b/src/com/bytezone/diskbrowser/gui/DuplicateAction.java
index f041364..922c5b8 100644
--- a/src/com/bytezone/diskbrowser/gui/DuplicateAction.java
+++ b/src/com/bytezone/diskbrowser/gui/DuplicateAction.java
@@ -1,12 +1,16 @@
 package com.bytezone.diskbrowser.gui;
 
+import java.awt.Toolkit;
 import java.awt.event.ActionEvent;
+import java.awt.event.KeyEvent;
 import java.io.File;
 
 import javax.swing.Action;
+import javax.swing.KeyStroke;
 
 import com.bytezone.common.DefaultAction;
 import com.bytezone.diskbrowser.duplicates.DuplicateWindow;
+import com.bytezone.diskbrowser.duplicates.DuplicateWorker;
 import com.bytezone.diskbrowser.gui.RootDirectoryAction.RootDirectoryChangeListener;
 
 public class DuplicateAction extends DefaultAction implements RootDirectoryChangeListener
@@ -22,6 +26,8 @@ public class DuplicateAction extends DefaultAction implements RootDirectoryChang
 
     setIcon (Action.SMALL_ICON, "save_delete_16.png");
     setIcon (Action.LARGE_ICON_KEY, "save_delete_32.png");
+    int mask = Toolkit.getDefaultToolkit ().getMenuShortcutKeyMask ();
+    putValue (Action.ACCELERATOR_KEY, KeyStroke.getKeyStroke (KeyEvent.VK_D, mask));
     setEnabled (false);
   }
 
@@ -37,7 +43,10 @@ public class DuplicateAction extends DefaultAction implements RootDirectoryChang
   public void actionPerformed (ActionEvent arg0)
   {
     if (window == null)
+    {
       window = new DuplicateWindow (rootFolder);
+      new DuplicateWorker (rootFolder, window).execute ();
+    }
     else
       window.setVisible (true);
   }
diff --git a/src/com/bytezone/diskbrowser/utilities/Utility.java b/src/com/bytezone/diskbrowser/utilities/Utility.java
index 07556f1..7a93841 100644
--- a/src/com/bytezone/diskbrowser/utilities/Utility.java
+++ b/src/com/bytezone/diskbrowser/utilities/Utility.java
@@ -69,8 +69,10 @@ public class Utility
     if (dotPos2 > 0)
     {
       String suffix2 = filename.substring (dotPos2 + 1, dotPos).toLowerCase ();
-      if (suffix.equals ("gz") && (suffix2.equals ("bxy") || suffix2.equals ("bny")))
-        return false;
+      //      if (suffix.equals ("gz") && (suffix2.equals ("bxy") || suffix2.equals ("bny")))
+      //        return false;
+      if (suffix.equals ("gz"))
+        return suffixes.contains (suffix2) && !"gz".equals (suffix2);
     }
 
     return suffixes.contains (suffix);