diff --git a/src/AddIns/BackendBindings/XamlBinding/XamlBinding/XamlParser.cs b/src/AddIns/BackendBindings/XamlBinding/XamlBinding/XamlParser.cs
index 971d2bebab..3fbc02c809 100644
--- a/src/AddIns/BackendBindings/XamlBinding/XamlBinding/XamlParser.cs
+++ b/src/AddIns/BackendBindings/XamlBinding/XamlBinding/XamlParser.cs
@@ -50,8 +50,8 @@ namespace ICSharpCode.XamlBinding
 			return false;
 		}
 		
-		AXmlParser axmlParser;
-		ICSharpCode.SharpDevelop.ITextBuffer lastParsedContent;
+		AXmlParser axmlParser = new AXmlParser();
+		volatile ICSharpCode.SharpDevelop.ITextBufferVersion lastParsedVersion;
 		
 		/// <summary>
 		/// Parse the given text and enter read lock.
@@ -59,21 +59,24 @@ namespace ICSharpCode.XamlBinding
 		/// </summary>
 		public IDisposable ParseAndLock(ICSharpCode.SharpDevelop.ITextBuffer fileContent)
 		{
-			// Is fileContent newer?
-			if (lastParsedContent == null || fileContent.Version.CompareAge(lastParsedContent.Version) > 0) {
+			// Copy to ensure thread-safety
+			var lastVer = lastParsedVersion;
+			if (lastVer == null ||                              // First parse
+			    fileContent.Version == null ||                  // Versioning not supported
+			    fileContent.Version.CompareAge(lastVer) > 0)    // Is fileContent newer?
+			{
 				axmlParser.Lock.EnterWriteLock();
 				// Dobuble check, now that we are thread-safe
-				if (lastParsedContent == null) {
-					// First parse
-					axmlParser = new AXmlParser();
+				if (lastParsedVersion == null || fileContent.Version == null) {
+					// First parse or verisoning not supported
 					axmlParser.Parse(fileContent.Text, null);
-					lastParsedContent = fileContent;
-				} else if (fileContent.Version.CompareAge(lastParsedContent.Version) > 0) {
+					lastParsedVersion = fileContent.Version;
+				} else if (fileContent.Version.CompareAge(lastParsedVersion) > 0) {
 					// Incremental parse
-					var changes = lastParsedContent.Version.GetChangesTo(fileContent.Version).
+					var changes = lastParsedVersion.GetChangesTo(fileContent.Version).
 						Select(c => new DocumentChangeEventArgs(c.Offset, c.RemovedText, c.InsertedText));
 					axmlParser.Parse(fileContent.Text, changes);
-					lastParsedContent = fileContent;
+					lastParsedVersion = fileContent.Version;
 				} else {
 					// fileContent is older - no need to parse
 				}
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Xml/AXmlParser.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Xml/AXmlParser.cs
index 079f7a4013..96bc1fb4ae 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Xml/AXmlParser.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Xml/AXmlParser.cs
@@ -136,8 +136,10 @@ namespace ICSharpCode.AvalonEdit.Xml
 		/// <summary>
 		/// Incrementaly parse the given text.
 		/// You have to hold the write lock.
-		/// 'changesSinceLastParse' can be null on the first call.
 		/// </summary>
+		/// <param name="changesSinceLastParse">
+		/// Changes since last parse.  Null will cause full reparse.
+		/// </param>
 		public AXmlDocument Parse(string input, IEnumerable<DocumentChangeEventArgs> changesSinceLastParse)
 		{
 			if (!Lock.IsWriteLockHeld)
@@ -146,6 +148,8 @@ namespace ICSharpCode.AvalonEdit.Xml
 			// Use changes to invalidate cache
 			if (changesSinceLastParse != null) {
 				this.TrackedSegments.UpdateOffsetsAndInvalidate(changesSinceLastParse);
+			} else {
+				this.TrackedSegments.InvalidateAll();
 			}
 			
 			TagReader tagReader = new TagReader(this, input);
diff --git a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Xml/TrackedSegmentCollection.cs b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Xml/TrackedSegmentCollection.cs
index 1b0055a484..767041796f 100644
--- a/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Xml/TrackedSegmentCollection.cs
+++ b/src/Libraries/AvalonEdit/ICSharpCode.AvalonEdit/Xml/TrackedSegmentCollection.cs
@@ -54,6 +54,18 @@ namespace ICSharpCode.AvalonEdit.Xml
 			}
 		}
 		
+		/// <summary>
+		/// Invlidates all objects.  That is, the whole document has changed.
+		/// </summary>
+		/// <remarks> We still have to keep the items becuase they might be in the document </remarks>
+		public void InvalidateAll()
+		{
+			AXmlParser.Log("Invalidating all objects");
+			foreach(AXmlObject obj in segments.OfType<AXmlObject>()) {
+				obj.IsCached = false;
+			}
+		}
+		
 		/// <summary> Add object to cache, optionally adding extra memory tracking </summary>
 		public void AddParsedObject(AXmlObject obj, int? maxTouchedLocation)
 		{