diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit.Tests/ICSharpCode.AvalonEdit.Tests.csproj b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit.Tests/ICSharpCode.AvalonEdit.Tests.csproj
index d81a412734..6798784599 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit.Tests/ICSharpCode.AvalonEdit.Tests.csproj
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit.Tests/ICSharpCode.AvalonEdit.Tests.csproj
@@ -19,6 +19,7 @@
     <WarningLevel>4</WarningLevel>
     <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
     <OutputPath>..\..\..\..\bin\UnitTests\</OutputPath>
+    <RunPostBuildEvent>OnBuildSuccess</RunPostBuildEvent>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
     <DebugSymbols>true</DebugSymbols>
@@ -38,7 +39,7 @@
     <RegisterForComInterop>False</RegisterForComInterop>
     <GenerateSerializationAssemblies>Auto</GenerateSerializationAssemblies>
     <BaseAddress>4194304</BaseAddress>
-    <PlatformTarget>AnyCPU</PlatformTarget>
+    <PlatformTarget>x86</PlatformTarget>
     <FileAlignment>4096</FileAlignment>
   </PropertyGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.Targets" />
@@ -87,6 +88,7 @@
     <Compile Include="Utils\RopeTests.cs" />
     <Compile Include="WeakReferenceTests.cs" />
     <Compile Include="XmlParser\ParserTests.cs" />
+    <Compile Include="XmlParser\TextReplacementTests.cs" />
     <None Include="app.config" />
     <None Include="XmlParser\W3C.zip">
       <CopyToOutputDirectory>Always</CopyToOutputDirectory>
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit.Tests/XmlParser/TextReplacementTests.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit.Tests/XmlParser/TextReplacementTests.cs
new file mode 100644
index 0000000000..7e82a95fb8
--- /dev/null
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit.Tests/XmlParser/TextReplacementTests.cs
@@ -0,0 +1,119 @@
+// <file>
+//     <copyright see="prj:///doc/copyright.txt"/>
+//     <license see="prj:///doc/license.txt"/>
+//     <owner name="Siegfried Pammer" email="siegfriedpammer@gmail.com" />
+//     <version>$Revision$</version>
+// </file>
+
+using System;
+using System.Collections.Generic;
+using ICSharpCode.AvalonEdit.Document;
+using ICSharpCode.AvalonEdit.Xml;
+using NUnit.Framework;
+
+namespace ICSharpCode.AvalonEdit.Xml
+{
+	[TestFixture]
+	public class TextReplacementTests
+	{
+		#region Test Data
+		string initialDocumentText = @"<UserControl x:Class='ICSharpCode.Profiler.Controls.TimeLineCell'
+	xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'
+	xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+	<Grid>
+		
+	</Grid>
+</UserControl>";
+		
+		string finalDocumentText = @"<UserControl x:Class='ICSharpCode.Profiler.Controls.TimeLineCell'
+	xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'
+	xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+			<Grid>
+				<Grid.RowDefinitions>
+					<RowDefinition Height='20' />
+					<RowDefinition Height='20' />
+					<RowDefinition Height='Auto' />
+				</Grid.RowDefinitions>
+				<StackPanel Orientation='Horizontal'>
+					<TextBlock Text='Test' />
+				</StackPanel>
+				<local:TimeLineControl x:Name='t1' Grid.Row='1' />
+				<TextBlock Grid.Row='2' Text='Test' />
+			</Grid>
+</UserControl>";
+		
+		int offset = @"<UserControl x:Class='ICSharpCode.Profiler.Controls.TimeLineCell'
+	xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'
+	xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+".Length;
+		
+		string original = @"	<Grid>
+		
+	</Grid>";
+		
+		string replacement = @"			<Grid>
+				<Grid.RowDefinitions>
+					<RowDefinition Height='20' />
+					<RowDefinition Height='20' />
+					<RowDefinition Height='Auto' />
+				</Grid.RowDefinitions>
+				<StackPanel Orientation='Horizontal'>
+					<TextBlock Text='Test' />
+				</StackPanel>
+				<local:TimeLineControl x:Name='t1' Grid.Row='1' />
+				<TextBlock Grid.Row='2' Text='Test' />
+			</Grid>";
+		#endregion
+		
+		[Test]
+		public void ReplacementTest1()
+		{
+			/*
+			 * REPRODUCTION STEPS
+			 * 
+			 * 1. Run XmlDOM project
+			 * 2. paste text from initialDocumentText (see Test Data region)
+			 * 3. select lines 4 to 6
+			 * 4. replace with replacement (see Test Data region)
+			 * 5. exception thrown:
+			 *    ICSharpCode.AvalonEdit.Xml.InternalException : Assertion failed: cached elements must not have zero length
+			 *    at ICSharpCode.AvalonEdit.Xml.AXmlParser.Assert(Boolean condition, String message)
+			 *  in c:\Projects\SharpDevelop\4.0\SharpDevelop\src\Libraries\AvalonEdit\ICSharpCode.AvalonEdit\Xml\AXmlParser.cs:line 121
+			 *    at ICSharpCode.AvalonEdit.Xml.TagReader.TryReadFromCacheOrNew[T](T& res, Predicate`1 condition)
+			 *  in c:\Projects\SharpDevelop\4.0\SharpDevelop\src\Libraries\AvalonEdit\ICSharpCode.AvalonEdit\Xml\TagReader.cs:line 39
+			 *    at ICSharpCode.AvalonEdit.Xml.TagReader.<ReadText>d__12.MoveNext()
+			 *  in c:\Projects\SharpDevelop\4.0\SharpDevelop\src\Libraries\AvalonEdit\ICSharpCode.AvalonEdit\Xml\TagReader.cs:line 456
+			 *    at System.Collections.Generic.List`1.InsertRange(Int32 index, IEnumerable`1 collection)
+			 *    at System.Collections.Generic.List`1.AddRange(IEnumerable`1 collection)
+			 *    at ICSharpCode.AvalonEdit.Xml.TagReader.ReadAllTags()
+			 *  in c:\Projects\SharpDevelop\4.0\SharpDevelop\src\Libraries\AvalonEdit\ICSharpCode.AvalonEdit\Xml\TagReader.cs:line 73
+			 *    at ICSharpCode.AvalonEdit.Xml.AXmlParser.Parse(String input, IEnumerable`1 changesSinceLastParse)
+			 *  in c:\Projects\SharpDevelop\4.0\SharpDevelop\src\Libraries\AvalonEdit\ICSharpCode.AvalonEdit\Xml\AXmlParser.cs:line 161
+			 *    at ICSharpCode.AvalonEdit.Tests.XmlParser.TextReplacementTests.RunTest()
+			 *  in c:\Projects\SharpDevelop\4.0\SharpDevelop\src\Libraries\AvalonEdit\ICSharpCode.AvalonEdit.Tests\XmlParser\TextReplacementTests.cs:line 114
+			 *    at ICSharpCode.AvalonEdit.Tests.XmlParser.TextReplacementTests.TestMethod(
+			 * ) in c:\Projects\SharpDevelop\4.0\SharpDevelop\src\Libraries\AvalonEdit\ICSharpCode.AvalonEdit.Tests\XmlParser\TextReplacementTests.cs:line 97
+			 * */
+			Assert.DoesNotThrow(RunTest1);
+		}
+		
+		void RunTest1()
+		{
+			AXmlParser parser = new AXmlParser();
+			
+			try {
+				parser.Lock.EnterWriteLock();
+				
+				parser.Parse(initialDocumentText, null); // full reparse
+				
+				IList<DocumentChangeEventArgs> changes = new List<DocumentChangeEventArgs>();
+				
+				changes.Add(new DocumentChangeEventArgs(offset, original, replacement));
+				
+				parser.Parse(finalDocumentText, changes);
+			} finally {
+				parser.Lock.ExitWriteLock();
+			}
+		}
+	}
+}
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Xml/TrackedSegmentCollection.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Xml/TrackedSegmentCollection.cs
index 32dbcb2c1f..92cb3e1ec0 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Xml/TrackedSegmentCollection.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Xml/TrackedSegmentCollection.cs
@@ -40,11 +40,11 @@ namespace ICSharpCode.AvalonEdit.Xml
 				segments.UpdateOffsets(change);
 				
 				// Remove any items affected by the change
-				AXmlParser.Log("Changed offset {0}", change.Offset);
+				AXmlParser.Log("Changed {0}-{1}", change.Offset, change.Offset + change.InsertionLength);
 				// Removing will cause one of the ends to be set to change.Offset
 				// FindSegmentsContaining includes any segments touching
 				// so that conviniently takes care of the +1 byte
-				var segmentsContainingOffset = segments.FindSegmentsContaining(change.Offset);
+				var segmentsContainingOffset = segments.FindOverlappingSegments(change.Offset, change.InsertionLength);
 				foreach(AXmlObject obj in segmentsContainingOffset.OfType<AXmlObject>().Where(o => o.IsCached)) {
 					InvalidateCache(obj, false);
 				}