diff --git a/src/Main/Base/Project/Src/Services/ParserService/DomHostCallback.cs b/src/Main/Base/Project/Src/Services/ParserService/DomHostCallback.cs
index 202ca51f2b..12a51a0b4c 100644
--- a/src/Main/Base/Project/Src/Services/ParserService/DomHostCallback.cs
+++ b/src/Main/Base/Project/Src/Services/ParserService/DomHostCallback.cs
@@ -6,6 +6,8 @@
 // </file>
 
 using System;
+using System.IO;
+using Microsoft.Win32;
 using ICSharpCode.Core;
 using ICSharpCode.SharpDevelop.Dom;
 using ICSharpCode.SharpDevelop.Gui;
@@ -45,6 +47,13 @@ namespace ICSharpCode.SharpDevelop
 			};
 			
 			HostCallback.InitializeCodeGeneratorOptions = AmbienceService.InitializeCodeGeneratorOptions;
+			
+			string dir = WinFXReferenceDirectory;
+			if (!string.IsNullOrEmpty(dir))
+				XmlDoc.XmlDocLookupDirectories.Add(dir);
+			dir = XNAReferenceDirectory;
+			if (!string.IsNullOrEmpty(dir))
+				XmlDoc.XmlDocLookupDirectories.Add(dir);
 		}
 		
 		static void ShowAssemblyLoadError(string fileName, string include, string message)
@@ -57,5 +66,33 @@ namespace ICSharpCode.SharpDevelop
 				) + "\r\n" + message + "\r\n"
 			);
 		}
+		
+		static string WinFXReferenceDirectory {
+			get {
+				RegistryKey k = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.0\Setup\Windows Communication Foundation");
+				if (k == null)
+					return null;
+				object o = k.GetValue("ReferenceInstallPath");
+				k.Close();
+				if (o == null)
+					return null;
+				else
+					return o.ToString();
+			}
+		}
+		
+		static string XNAReferenceDirectory {
+			get {
+				RegistryKey k = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\XNA\Game Studio Express\v1.0");
+				if (k == null)
+					return null;
+				object o = k.GetValue("InstallPath");
+				k.Close();
+				if (o == null)
+					return null;
+				else
+					return Path.Combine(o.ToString(), @"References\Windows\x86");
+			}
+		}
 	}
 }
diff --git a/src/Main/ICSharpCode.SharpDevelop.Dom/Project/Src/ProjectContent/ReflectionProjectContent.cs b/src/Main/ICSharpCode.SharpDevelop.Dom/Project/Src/ProjectContent/ReflectionProjectContent.cs
index 661691f47d..4b1f5706a9 100644
--- a/src/Main/ICSharpCode.SharpDevelop.Dom/Project/Src/ProjectContent/ReflectionProjectContent.cs
+++ b/src/Main/ICSharpCode.SharpDevelop.Dom/Project/Src/ProjectContent/ReflectionProjectContent.cs
@@ -9,7 +9,6 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Reflection;
-using Microsoft.Win32;
 
 using ICSharpCode.SharpDevelop.Dom.ReflectionLayer;
 
@@ -116,16 +115,12 @@ namespace ICSharpCode.SharpDevelop.Dom
 			}
 			
 			string fileName = LookupLocalizedXmlDoc(assemblyLocation);
-			// Not found -> look in runtime directory.
 			if (fileName == null) {
-				string runtimeDirectory = System.Runtime.InteropServices.RuntimeEnvironment.GetRuntimeDirectory();
-				fileName = LookupLocalizedXmlDoc(Path.Combine(runtimeDirectory, Path.GetFileName(assemblyLocation)));
-			}
-			if (fileName == null) {
-				// still not found -> look in WinFX reference directory
-				string referenceDirectory = WinFXReferenceDirectory;
-				if (!string.IsNullOrEmpty(referenceDirectory)) {
-					fileName = LookupLocalizedXmlDoc(Path.Combine(referenceDirectory, Path.GetFileName(assemblyLocation)));
+				// Not found -> look in other directories:
+				foreach (string testDirectory in XmlDoc.XmlDocLookupDirectories) {
+					fileName = LookupLocalizedXmlDoc(Path.Combine(testDirectory, Path.GetFileName(assemblyLocation)));
+					if (fileName != null)
+						break;
 				}
 			}
 			
@@ -134,20 +129,6 @@ namespace ICSharpCode.SharpDevelop.Dom
 			}
 		}
 		
-		static string WinFXReferenceDirectory {
-			get {
-				RegistryKey k = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\NET Framework Setup\NDP\v3.0\Setup\Windows Communication Foundation");
-				if (k == null)
-					return null;
-				object o = k.GetValue("ReferenceInstallPath");
-				k.Close();
-				if (o == null)
-					return null;
-				else
-					return o.ToString();
-			}
-		}
-		
 		public void InitializeSpecialClasses()
 		{
 			if (GetClassInternal(VoidClass.VoidName, 0, Language) != null) {
diff --git a/src/Main/ICSharpCode.SharpDevelop.Dom/Project/Src/XmlDoc.cs b/src/Main/ICSharpCode.SharpDevelop.Dom/Project/Src/XmlDoc.cs
index c0d5bc2060..0169334f09 100644
--- a/src/Main/ICSharpCode.SharpDevelop.Dom/Project/Src/XmlDoc.cs
+++ b/src/Main/ICSharpCode.SharpDevelop.Dom/Project/Src/XmlDoc.cs
@@ -18,6 +18,14 @@ namespace ICSharpCode.SharpDevelop.Dom
 	/// </summary>
 	public sealed class XmlDoc : IDisposable
 	{
+		static readonly List<string> xmlDocLookupDirectories = new List<string>(
+			new string[] { System.Runtime.InteropServices.RuntimeEnvironment.GetRuntimeDirectory() }
+		);
+		
+		public static IList<string> XmlDocLookupDirectories {
+			get { return xmlDocLookupDirectories; }
+		}
+		
 		struct IndexEntry : IComparable<IndexEntry>
 		{
 			public int HashCode;