diff --git a/ChangeLog b/ChangeLog
index 669f2a1d5..fecff2fe7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2012-08-21  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
+
+	* OpenChange/MAPIStoreGCSFolder.m
+	(-setChangeKey:forMessageWithKey:): removed useless method.
+	(-updateVersionsForMessageWithKey:withChangeKey:): set the change
+	key provided by the client as member of the predecessor
+	changelist, but never as the actual change key for the object.
+	This hopefully fixes the issue where Outlook deletes objects that
+	have a different change list than what they expect.
+
 2012-08-17  Wolfgang Sourdeau  <wsourdeau@inverse.ca>
 
 	* OpenChange/MAPIStoreCalendarMessage.m
diff --git a/OpenChange/MAPIStoreGCSFolder.h b/OpenChange/MAPIStoreGCSFolder.h
index 6d25069ca..1f48e034a 100644
--- a/OpenChange/MAPIStoreGCSFolder.h
+++ b/OpenChange/MAPIStoreGCSFolder.h
@@ -45,11 +45,8 @@
                            withChangeKey: (NSData *) newChangeKey;
 - (NSNumber *) lastModifiedFromMessageChangeNumber: (NSNumber *) changeNum;
 - (NSNumber *) changeNumberForMessageWithKey: (NSString *) messageKey;
-
 - (NSData *) changeKeyForMessageWithKey: (NSString *) messageKey;
 - (NSData *) predecessorChangeListForMessageWithKey: (NSString *) messageKey;
-- (void) setChangeKey: (NSData *) changeKey
-    forMessageWithKey: (NSString *) messageKey;
 
 - (NSArray *) activeUserRoles;
 
diff --git a/OpenChange/MAPIStoreGCSFolder.m b/OpenChange/MAPIStoreGCSFolder.m
index d042dfcf0..a5702131f 100644
--- a/OpenChange/MAPIStoreGCSFolder.m
+++ b/OpenChange/MAPIStoreGCSFolder.m
@@ -261,6 +261,7 @@ static Class NSNumberK;
 
 - (void) _setChangeKey: (NSData *) changeKey
        forMessageEntry: (NSMutableDictionary *) messageEntry
+      inChangeListOnly: (BOOL) inChangeListOnly
 {
   struct XID *xid;
   NSString *guid;
@@ -273,12 +274,15 @@ static Class NSNumberK;
   globCnt = [NSData dataWithBytes: xid->Data length: xid->Size];
   talloc_free (xid);
 
-  /* 1. set change key association */
-  changeKeyDict = [NSDictionary dictionaryWithObjectsAndKeys:
-                                  guid, @"GUID",
-                                globCnt, @"LocalId",
-                                nil];
-  [messageEntry setObject: changeKeyDict forKey: @"ChangeKey"];
+  if (!inChangeListOnly)
+    {
+      /* 1. set change key association */
+      changeKeyDict = [NSDictionary dictionaryWithObjectsAndKeys:
+                                      guid, @"GUID",
+                                    globCnt, @"LocalId",
+                                    nil];
+      [messageEntry setObject: changeKeyDict forKey: @"ChangeKey"];
+    }
 
   /* 2. append/update predecessor change list */
   changeList = [messageEntry objectForKey: @"PredecessorChangeList"];
@@ -286,11 +290,10 @@ static Class NSNumberK;
     {
       changeList = [NSMutableDictionary new];
       [messageEntry setObject: changeList
-                    forKey: @"PredecessorChangeList"];
+                       forKey: @"PredecessorChangeList"];
       [changeList release];
     }
-  [changeList setObject: globCnt
-                 forKey: guid];
+  [changeList setObject: globCnt forKey: guid];
 }
 
 - (EOQualifier *) componentQualifier
@@ -433,7 +436,8 @@ static Class NSNumberK;
               [messageEntry setObject: changeNumber forKey: @"version"];
 
               changeKey = [self getReplicaKeyFromGlobCnt: newChangeNum >> 16];
-              [self _setChangeKey: changeKey forMessageEntry: messageEntry];
+              [self _setChangeKey: changeKey forMessageEntry: messageEntry
+                 inChangeListOnly: NO];
 
               [mapping setObject: cLastModified forKey: changeNumber];
 
@@ -464,10 +468,21 @@ static Class NSNumberK;
 - (void) updateVersionsForMessageWithKey: (NSString *) messageKey
                            withChangeKey: (NSData *) newChangeKey
 {
-  [self synchroniseCache];
+  NSMutableDictionary *messages, *messageEntry;
 
+  [self synchroniseCache];
   if (newChangeKey)
-    [self setChangeKey: newChangeKey forMessageWithKey: messageKey];
+    {
+      messages = [[versionsMessage properties] objectForKey: @"Messages"];
+      messageEntry = [messages objectForKey: messageKey];
+      if (!messageEntry)
+        [NSException raise: @"MAPIStoreIOException"
+                    format: @"no version record found for message '%@'",
+                     messageKey];
+      [self _setChangeKey: newChangeKey forMessageEntry: messageEntry
+         inChangeListOnly: YES];
+      [versionsMessage save];
+    }
 }
  
 - (NSNumber *) lastModifiedFromMessageChangeNumber: (NSNumber *) changeNum
@@ -493,26 +508,6 @@ static Class NSNumberK;
   return changeNumber;
 }
 
-- (void) setChangeKey: (NSData *) changeKey
-    forMessageWithKey: (NSString *) messageKey
-{
-  NSMutableDictionary *messages;
-  NSMutableDictionary *messageEntry;
-
-  messages = [[versionsMessage properties] objectForKey: @"Messages"];
-  messageEntry = [messages objectForKey: messageKey];
-  if (!messageEntry)
-    {
-      [self synchroniseCache];
-      messageEntry = [messages objectForKey: messageKey];
-      if (!messageEntry)
-        abort ();
-    }
-  [self _setChangeKey: changeKey forMessageEntry: messageEntry];
-  
-  [versionsMessage save];
-}
-
 - (NSData *) changeKeyForMessageWithKey: (NSString *) messageKey
 {
   NSDictionary *messages, *changeKeyDict;