diff --git a/src/Main/Base/Project/Src/Gui/Workbench/DefaultWorkbench.cs b/src/Main/Base/Project/Src/Gui/Workbench/DefaultWorkbench.cs
index 7d15aacbae..d1f069e8bb 100644
--- a/src/Main/Base/Project/Src/Gui/Workbench/DefaultWorkbench.cs
+++ b/src/Main/Base/Project/Src/Gui/Workbench/DefaultWorkbench.cs
@@ -269,15 +269,20 @@ namespace ICSharpCode.SharpDevelop.Gui
 			StatusBarService.RedrawStatusbar();
 		}
 		
+		string GetMementoFileName(string contentName)
+		{
+			string directory = Path.Combine(PropertyService.ConfigDirectory, "temp");
+			//string directoryName = Path.GetDirectoryName(contentName);
+			return Path.Combine(directory,
+			                    Path.GetFileName(contentName)
+			                    + "." + contentName.ToLowerInvariant().GetHashCode().ToString("x")
+			                    + ".xml");
+		}
+		
 		public Properties GetStoredMemento(IViewContent content)
 		{
 			if (content != null && content.FileName != null) {
-				string directory = Path.Combine(PropertyService.ConfigDirectory, "temp");
-				if (!Directory.Exists(directory)) {
-					Directory.CreateDirectory(directory);
-				}
-				string fileName = content.FileName.Substring(3).Replace('/', '.').Replace('\\', '.').Replace(Path.DirectorySeparatorChar, '.');
-				string fullFileName = Path.Combine(directory, fileName);
+				string fullFileName = GetMementoFileName(content.FileName);
 				// check the file name length because it could be more than the maximum length of a file name
 				
 				if (FileUtility.IsValidFileName(fullFileName) && File.Exists(fullFileName)) {
@@ -299,8 +304,7 @@ namespace ICSharpCode.SharpDevelop.Gui
 			}
 			
 			Properties memento = ((IMementoCapable)content).CreateMemento();
-			string fileName = content.FileName.Substring(3).Replace('/', '.').Replace('\\', '.').Replace(Path.DirectorySeparatorChar, '.');
-			string fullFileName = Path.Combine(directory, fileName);
+			string fullFileName = GetMementoFileName(content.FileName);
 			
 			if (FileUtility.IsValidFileName(fullFileName)) {
 				FileUtility.ObservedSave(new NamedFileOperationDelegate(memento.Save), fullFileName, FileErrorPolicy.Inform);
diff --git a/src/Main/Base/Project/Src/Services/ProjectService/ProjectService.cs b/src/Main/Base/Project/Src/Services/ProjectService/ProjectService.cs
index 54e8cf0d1f..f0a07ed47c 100644
--- a/src/Main/Base/Project/Src/Services/ProjectService/ProjectService.cs
+++ b/src/Main/Base/Project/Src/Services/ProjectService/ProjectService.cs
@@ -296,9 +296,10 @@ namespace ICSharpCode.SharpDevelop.Project
 		static string GetPreferenceFileName(string projectFileName)
 		{
 			string directory = PropertyService.ConfigDirectory + "preferences";
-			string fileName = projectFileName.Substring(3).Replace('/', '.').Replace('\\', '.').Replace(Path.DirectorySeparatorChar, '.');
-			string fullFileName = Path.Combine(directory, fileName + ".xml");
-			return fullFileName;
+			return Path.Combine(directory,
+			                    Path.GetFileName(projectFileName)
+			                    + "." + projectFileName.ToLowerInvariant().GetHashCode().ToString("x")
+			                    + ".xml");
 		}
 		
 		public static void SaveSolutionPreferences()
diff --git a/src/Main/Core/Project/Src/Services/FileUtility/FileUtility.cs b/src/Main/Core/Project/Src/Services/FileUtility/FileUtility.cs
index 289d71447b..58db370b0f 100644
--- a/src/Main/Core/Project/Src/Services/FileUtility/FileUtility.cs
+++ b/src/Main/Core/Project/Src/Services/FileUtility/FileUtility.cs
@@ -265,6 +265,8 @@ namespace ICSharpCode.Core
 			}
 		}
 		
+		public static int MaxPathLength = 260;
+		
 		/// <summary>
 		/// This method checks the file fileName if it is valid.
 		/// </summary>
@@ -273,7 +275,7 @@ namespace ICSharpCode.Core
 			// Fixme: 260 is the hardcoded maximal length for a path on my Windows XP system
 			//        I can't find a .NET property or method for determining this variable.
 			
-			if (fileName == null || fileName.Length == 0 || fileName.Length >= 260) {
+			if (fileName == null || fileName.Length == 0 || fileName.Length >= MaxPathLength) {
 				return false;
 			}