diff --git a/PluginCommon/PluginManager.cs b/PluginCommon/PluginManager.cs
index 8a5d847..754e83e 100644
--- a/PluginCommon/PluginManager.cs
+++ b/PluginCommon/PluginManager.cs
@@ -132,14 +132,16 @@ namespace PluginCommon {
         /// Generates a list of references to instances of active plugins.
         /// </summary>
         /// <returns>Newly-created list of plugin references.</returns>
-        public List<IPlugin> GetActivePlugins() {
-            List<IPlugin> list = new List<IPlugin>(mActivePlugins.Count);
+        public Dictionary<string, IPlugin> GetActivePlugins() {
+            Dictionary<string, IPlugin> dict =
+                new Dictionary<string, IPlugin>(mActivePlugins.Count);
             foreach (KeyValuePair<string, IPlugin> kvp in mActivePlugins) {
-                list.Add(kvp.Value);
+                // copy the contents; probably not necessary across AppDomain
+                dict.Add(kvp.Key, kvp.Value);
             }
-            Debug.WriteLine("PluginManager: returning " + list.Count + " plugins (id=" +
+            Debug.WriteLine("PluginManager: returning " + dict.Count + " plugins (id=" +
                 AppDomain.CurrentDomain.Id + ")");
-            return list;
+            return dict;
         }
 
         /// <summary>
diff --git a/SourceGen/DisasmProject.cs b/SourceGen/DisasmProject.cs
index 3787c56..ef43cf2 100644
--- a/SourceGen/DisasmProject.cs
+++ b/SourceGen/DisasmProject.cs
@@ -2496,9 +2496,12 @@ namespace SourceGen {
         }
 
         // Punch-through functions; trying to avoid exposing ScriptManager for now.
-        public List<PluginCommon.IPlugin> GetActivePlugins() {
+        public Dictionary<string, PluginCommon.IPlugin> GetActivePlugins() {
             return mScriptManager.GetActivePlugins();
         }
+        public PluginCommon.IPlugin GetPlugin(string scriptIdent) {
+            return mScriptManager.GetInstance(scriptIdent);
+        }
         public void PrepareScripts(PluginCommon.IApplication appRef) {
             mScriptManager.PrepareScripts(appRef);
         }
diff --git a/SourceGen/Sandbox/ScriptManager.cs b/SourceGen/Sandbox/ScriptManager.cs
index 931ebf0..1bb53ec 100644
--- a/SourceGen/Sandbox/ScriptManager.cs
+++ b/SourceGen/Sandbox/ScriptManager.cs
@@ -140,15 +140,17 @@ namespace SourceGen.Sandbox {
         /// </summary>
         /// <returns>Newly-created list of plugin references.</returns>
         public List<IPlugin> GetAllInstances() {
+            Dictionary<string, IPlugin> dict;
             if (DomainMgr == null) {
-                List<IPlugin> list = new List<IPlugin>(mActivePlugins.Count);
-                foreach (KeyValuePair<string, IPlugin> kvp in mActivePlugins) {
-                    list.Add(kvp.Value);
-                }
-                return list;
+                dict = mActivePlugins;
             } else {
-                return DomainMgr.PluginMgr.GetActivePlugins();
+                dict = DomainMgr.PluginMgr.GetActivePlugins();
             }
+            List<IPlugin> list = new List<IPlugin>(dict.Count);
+            foreach (KeyValuePair<string, IPlugin> kvp in dict) {
+                list.Add(kvp.Value);
+            }
+            return list;
         }
 
         /// <summary>
@@ -272,36 +274,36 @@ namespace SourceGen.Sandbox {
             return plSymbols;
         }
 
+#if false
         public delegate bool CheckMatch(IPlugin plugin);
         public IPlugin GetMatchingScript(CheckMatch check) {
+            Dictionary<string, IPlugin> plugins;
             if (DomainMgr == null) {
-                foreach (KeyValuePair<string, IPlugin> kvp in mActivePlugins) {
-                    if (check(kvp.Value)) {
-                        return kvp.Value;
-                    }
-                }
+                plugins = mActivePlugins;
             } else {
-                List<IPlugin> plugins = DomainMgr.PluginMgr.GetActivePlugins();
-                foreach (IPlugin plugin in plugins) {
-                    if (check(plugin)) {
-                        return plugin;
-                    }
+                plugins = DomainMgr.PluginMgr.GetActivePlugins();
+            }
+            foreach (IPlugin plugin in plugins.Values) {
+                if (check(plugin)) {
+                    return plugin;
                 }
             }
             return null;
         }
+#endif
 
         /// <summary>
         /// Returns a list of loaded plugins.  Callers should not retain this list, as the
         /// set can change due to user activity.
         /// </summary>
-        public List<IPlugin> GetActivePlugins() {
+        public Dictionary<string, IPlugin> GetActivePlugins() {
             if (DomainMgr == null) {
-                List<IPlugin> plist = new List<IPlugin>();
+                // copy the contents
+                Dictionary<string, IPlugin> pdict = new Dictionary<string, IPlugin>();
                 foreach (KeyValuePair<string, IPlugin> kvp in mActivePlugins) {
-                    plist.Add(kvp.Value);
+                    pdict.Add(kvp.Key, kvp.Value);
                 }
-                return plist;
+                return pdict;
             } else {
                 return DomainMgr.PluginMgr.GetActivePlugins();
             }
@@ -322,8 +324,8 @@ namespace SourceGen.Sandbox {
                     DebugGetScriptInfo(kvp.Value, sb);
                 }
             } else {
-                List<IPlugin> plugins = DomainMgr.PluginMgr.GetActivePlugins();
-                foreach (IPlugin plugin in plugins) {
+                Dictionary<string, IPlugin> plugins = DomainMgr.PluginMgr.GetActivePlugins();
+                foreach (IPlugin plugin in plugins.Values) {
                     string loc = DomainMgr.PluginMgr.GetPluginAssemblyLocation(plugin);
                     sb.AppendFormat("[sub {0}] ", DomainMgr.Id);
                     sb.Append(loc);
diff --git a/SourceGen/VisualizationSet.cs b/SourceGen/VisualizationSet.cs
index 51581ea..5887236 100644
--- a/SourceGen/VisualizationSet.cs
+++ b/SourceGen/VisualizationSet.cs
@@ -174,7 +174,7 @@ namespace SourceGen {
         /// <param name="project">Project reference.</param>
         public static void RefreshAllThumbnails(DisasmProject project) {
             ScriptSupport iapp = null;
-            List<IPlugin> plugins = null;
+            Dictionary<string, IPlugin> plugins = null;
 
             SortedList<int, VisualizationSet> visSets = project.VisualizationSets;
 
@@ -248,9 +248,9 @@ namespace SourceGen {
         /// <param name="plugins">List of plugins, from project ScriptManager.</param>
         /// <param name="visGenIdent">Visualization generator identifier.</param>
         /// <returns>A plugin that matches, or null if none found.</returns>
-        private static IPlugin_Visualizer FindPluginByVisGenIdent(List<IPlugin> plugins,
-                string visGenIdent, out VisDescr visDescr) {
-            foreach (IPlugin chkPlug in plugins) {
+        private static IPlugin_Visualizer FindPluginByVisGenIdent(
+                Dictionary<string, IPlugin> plugins, string visGenIdent, out VisDescr visDescr) {
+            foreach (IPlugin chkPlug in plugins.Values) {
                 if (!(chkPlug is IPlugin_Visualizer)) {
                     continue;
                 }
diff --git a/SourceGen/WpfGui/EditVisualization.xaml.cs b/SourceGen/WpfGui/EditVisualization.xaml.cs
index 7cc90c8..9d87002 100644
--- a/SourceGen/WpfGui/EditVisualization.xaml.cs
+++ b/SourceGen/WpfGui/EditVisualization.xaml.cs
@@ -84,13 +84,15 @@ namespace SourceGen.WpfGui {
         /// </summary>
         /// <remarks>
         /// Strictly speaking we could just create an ItemsSource from VisDescr objects, but
-        /// the plugin reference saves a lookup later.
+        /// the plugin reference saves a lookup later.  We store the script ident rather than
+        /// an IPlugin reference because our reference would be a proxy object that expires,
+        /// and there's no value in creating a Sponsor<> or playing keep-alive.
         /// </remarks>
         public class VisualizationItem {
-            public IPlugin_Visualizer Plugin { get; private set; }
+            public string ScriptIdent { get; private set; }
             public VisDescr VisDescriptor { get; private set; }
-            public VisualizationItem(IPlugin_Visualizer plugin, VisDescr descr) {
-                Plugin = plugin;
+            public VisualizationItem(string scriptIdent, VisDescr descr) {
+                ScriptIdent = scriptIdent;
                 VisDescriptor = descr;
             }
         }
@@ -198,12 +200,12 @@ namespace SourceGen.WpfGui {
 
             int visSelection = -1;
             VisualizationList = new List<VisualizationItem>();
-            List<IPlugin> plugins = proj.GetActivePlugins();
-            foreach (IPlugin chkPlug in plugins) {
-                if (!(chkPlug is IPlugin_Visualizer)) {
+            Dictionary<string, IPlugin> plugins = proj.GetActivePlugins();
+            foreach (KeyValuePair<string, IPlugin> kvp in plugins) {
+                if (!(kvp.Value is IPlugin_Visualizer)) {
                     continue;
                 }
-                IPlugin_Visualizer vplug = (IPlugin_Visualizer)chkPlug;
+                IPlugin_Visualizer vplug = (IPlugin_Visualizer)kvp.Value;
                 foreach (VisDescr descr in vplug.GetVisGenDescrs()) {
                     if (vis != null && vis.VisGenIdent == descr.Ident) {
                         // found matching descriptor, set selection to this
@@ -212,7 +214,7 @@ namespace SourceGen.WpfGui {
                         // we used this one last time, use it if nothing better comes along
                         visSelection = VisualizationList.Count;
                     }
-                    VisualizationList.Add(new VisualizationItem(vplug, descr));
+                    VisualizationList.Add(new VisualizationItem(kvp.Key, descr));
                 }
             }
 
@@ -437,8 +439,9 @@ namespace SourceGen.WpfGui {
 
                 IVisualization2d vis2d;
                 try {
-                    vis2d = item.Plugin.Generate2d(item.VisDescriptor,
-                        CreateVisGenParams());
+                    IPlugin_Visualizer plugin =
+                        (IPlugin_Visualizer)mProject.GetPlugin(item.ScriptIdent);
+                    vis2d = plugin.Generate2d(item.VisDescriptor, CreateVisGenParams());
                     if (vis2d == null) {
                         Debug.WriteLine("Vis generator returned null");
                     }
diff --git a/SourceGen/WpfGui/EditVisualizationSet.xaml.cs b/SourceGen/WpfGui/EditVisualizationSet.xaml.cs
index f75828b..9b72f34 100644
--- a/SourceGen/WpfGui/EditVisualizationSet.xaml.cs
+++ b/SourceGen/WpfGui/EditVisualizationSet.xaml.cs
@@ -125,8 +125,8 @@ namespace SourceGen.WpfGui {
             }
 
             // Check to see if we have any relevant plugins.  If not, disable New/Edit.
-            List<IPlugin> plugins = project.GetActivePlugins();
-            foreach (IPlugin chkPlug in plugins) {
+            Dictionary<string, IPlugin> plugins = project.GetActivePlugins();
+            foreach (IPlugin chkPlug in plugins.Values) {
                 if (chkPlug is IPlugin_Visualizer) {
                     HasVisPlugins = true;
                     break;