diff --git a/SourceGen/DataAnalysis.cs b/SourceGen/DataAnalysis.cs
index 5290155..db22390 100644
--- a/SourceGen/DataAnalysis.cs
+++ b/SourceGen/DataAnalysis.cs
@@ -303,11 +303,15 @@ namespace SourceGen {
                     // (Note the uncategorized data pass hasn't run yet, so only instructions
                     // and offsets identified by users or scripts have been categorized.)
                     int scanOffset = targetOffset;
-                    while (--scanOffset > 0) {
+                    while (--scanOffset >= 0) {
                         FormatDescriptor dfd = mAnattribs[scanOffset].DataDescriptor;
-                        if (dfd != null && scanOffset + dfd.Length > targetOffset) {
-                            // Descriptor encompasses target offset.  Adjust target.
-                            targetOffset = scanOffset;
+                        if (dfd != null) {
+                            if (scanOffset + dfd.Length > targetOffset) {
+                                // Found a descriptor that encompasses target offset.  Adjust
+                                // target to point at the start of the region.
+                                targetOffset = scanOffset;
+                            }
+                            // Descriptors aren't allowed to overlap, so either way we're done.
                             break;
                         }
                     }
diff --git a/SourceGen/DisasmProject.cs b/SourceGen/DisasmProject.cs
index 3e97253..c61fd26 100644
--- a/SourceGen/DisasmProject.cs
+++ b/SourceGen/DisasmProject.cs
@@ -1308,6 +1308,7 @@ namespace SourceGen {
             int offset = 0;
             while (offset < mFileData.Length) {
                 Anattrib attr = mAnattribs[offset];
+                bool thisIsCode = attr.IsInstructionStart;
                 Debug.Assert(attr.IsStart);
                 Debug.Assert(attr.Length != 0);
                 offset += attr.Length;
@@ -1321,6 +1322,12 @@ namespace SourceGen {
                     extraInstrBytes++;
                     offset++;
                 }
+
+                // Make sure the extra code bytes were part of an instruction.  Otherwise it
+                // means we moved from the end of a data area to the middle of an instruction,
+                // which is very bad.
+                Debug.Assert(extraInstrBytes == 0 || thisIsCode);
+
                 //if (extraInstrBytes > 0) { Debug.WriteLine("EIB=" + extraInstrBytes); }
                 // Max instruction len is 4, so the stray part must be shorter.
                 Debug.Assert(extraInstrBytes < 4);
diff --git a/SourceGen/RuntimeData/Help/settings.html b/SourceGen/RuntimeData/Help/settings.html
index 397d3e6..8477a2d 100644
--- a/SourceGen/RuntimeData/Help/settings.html
+++ b/SourceGen/RuntimeData/Help/settings.html
@@ -231,8 +231,10 @@ value.  If it's not checked, anything that isn't detected as code or
 explicitly formatted as data will be shown as individual byte values.</p>
 <p>If "seek nearby targets" is checked, the analyzer will try to use
 nearby labels for data loads and stores, adjusting them to fit
-(e.g. <code>LDA LABEL+1</code>).  If not enabled, labels are only used
-when they match exactly.</p>
+(e.g. <code>LDA LABEL+1</code>).  If not enabled, labels are not applied
+unless they match exactly.  Note that references into the middle of an
+instruction or formatted data area are always adjusted, regardless of
+how this is set.  This setting has no effect on local variables.</p>
 <p>If "smart PLP handling" is checked, the analyzer will try to use
 the processor status flags from a nearby <code>PHP</code> when a
 <code>PLP</code> is encountered.  If not enabled, all flags are set to
diff --git a/SourceGen/SourceGen.csproj b/SourceGen/SourceGen.csproj
index a060190..38e2e67 100644
--- a/SourceGen/SourceGen.csproj
+++ b/SourceGen/SourceGen.csproj
@@ -109,6 +109,9 @@
     <Compile Include="WpfGui\EditInstructionOperand.xaml.cs">
       <DependentUpon>EditInstructionOperand.xaml</DependentUpon>
     </Compile>
+    <Compile Include="WpfGui\EditInstructionOperand2.xaml.cs">
+      <DependentUpon>EditInstructionOperand2.xaml</DependentUpon>
+    </Compile>
     <Compile Include="WpfGui\EditLabel.xaml.cs">
       <DependentUpon>EditLabel.xaml</DependentUpon>
     </Compile>
@@ -266,6 +269,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="WpfGui\EditInstructionOperand2.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="WpfGui\EditLabel.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>