diff --git a/reactos/subsys/win32k/include/msgqueue.h b/reactos/subsys/win32k/include/msgqueue.h
index ea7a032bd47..9417b420fa0 100644
--- a/reactos/subsys/win32k/include/msgqueue.h
+++ b/reactos/subsys/win32k/include/msgqueue.h
@@ -144,12 +144,17 @@ VOID FASTCALL
 MsqIncPaintCountQueue(PUSER_MESSAGE_QUEUE Queue);
 VOID FASTCALL
 MsqDecPaintCountQueue(PUSER_MESSAGE_QUEUE Queue);
-LRESULT STDCALL
+LRESULT FASTCALL
 IntSendMessage(HWND hWnd,
 		UINT Msg,
 		WPARAM wParam,
 		LPARAM lParam);
-LRESULT STDCALL
+LRESULT FASTCALL
+IntPostOrSendMessage(HWND hWnd,
+		     UINT Msg,
+		     WPARAM wParam,
+		     LPARAM lParam);
+LRESULT FASTCALL
 IntSendMessageTimeout(HWND hWnd,
                       UINT Msg,
                       WPARAM wParam,
@@ -162,9 +167,9 @@ IntDispatchMessage(MSG* Msg);
 BOOL FASTCALL
 IntTranslateKbdMessage(LPMSG lpMsg, HKL dwhkl);
 
-VOID STDCALL
+VOID FASTCALL
 MsqPostKeyboardMessage(UINT uMsg, WPARAM wParam, LPARAM lParam);
-VOID STDCALL
+VOID FASTCALL
 MsqPostHotKeyMessage(PVOID Thread, HWND hWnd, WPARAM wParam, LPARAM lParam);
 VOID FASTCALL
 MsqInsertSystemMessage(MSG* Msg, BOOL RemMouseMoveMsg);
diff --git a/reactos/subsys/win32k/ntuser/focus.c b/reactos/subsys/win32k/ntuser/focus.c
index 59fcfb7bbc9..5fad4ae574c 100644
--- a/reactos/subsys/win32k/ntuser/focus.c
+++ b/reactos/subsys/win32k/ntuser/focus.c
@@ -16,7 +16,7 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  *
- * $Id: focus.c,v 1.19 2004/02/24 13:27:03 weiden Exp $
+ * $Id: focus.c,v 1.20 2004/04/13 13:50:31 weiden Exp $
  */
 
 #include <win32k/win32k.h>
@@ -58,8 +58,8 @@ IntSendDeactivateMessages(HWND hWndPrev, HWND hWnd)
 {
    if (hWndPrev)
    {
-      IntSendMessage(hWndPrev, WM_NCACTIVATE, FALSE, 0);
-      IntSendMessage(hWndPrev, WM_ACTIVATE,
+      IntPostOrSendMessage(hWndPrev, WM_NCACTIVATE, FALSE, 0);
+      IntPostOrSendMessage(hWndPrev, WM_ACTIVATE,
          MAKEWPARAM(WA_INACTIVE, NtUserGetWindowLong(hWndPrev, GWL_STYLE, FALSE) & WS_MINIMIZE),
          (LPARAM)hWnd);
    }
@@ -71,9 +71,9 @@ IntSendActivateMessages(HWND hWndPrev, HWND hWnd, BOOL MouseActivate)
    if (hWnd)
    {
       /* Send palette messages */
-      if (IntSendMessage(hWnd, WM_QUERYNEWPALETTE, 0, 0))
+      if (IntPostOrSendMessage(hWnd, WM_QUERYNEWPALETTE, 0, 0))
       {
-         IntSendMessage(HWND_BROADCAST, WM_PALETTEISCHANGING,
+         IntPostOrSendMessage(HWND_BROADCAST, WM_PALETTEISCHANGING,
             (WPARAM)hWnd, 0);
       }
 
@@ -83,9 +83,9 @@ IntSendActivateMessages(HWND hWndPrev, HWND hWnd, BOOL MouseActivate)
 
       /* FIXME: IntIsWindow */
 
-      IntSendMessage(hWnd, WM_NCACTIVATE, (WPARAM)(hWnd == NtUserGetForegroundWindow()), 0);
+      IntPostOrSendMessage(hWnd, WM_NCACTIVATE, (WPARAM)(hWnd == NtUserGetForegroundWindow()), 0);
       /* FIXME: WA_CLICKACTIVE */
-      IntSendMessage(hWnd, WM_ACTIVATE,
+      IntPostOrSendMessage(hWnd, WM_ACTIVATE,
          MAKEWPARAM(MouseActivate ? WA_CLICKACTIVE : WA_ACTIVE,
                     NtUserGetWindowLong(hWnd, GWL_STYLE, FALSE) & WS_MINIMIZE),
          (LPARAM)hWndPrev);
@@ -97,7 +97,7 @@ IntSendKillFocusMessages(HWND hWndPrev, HWND hWnd)
 {
    if (hWndPrev)
    {
-      IntSendMessage(hWndPrev, WM_KILLFOCUS, (WPARAM)hWnd, 0);
+      IntPostOrSendMessage(hWndPrev, WM_KILLFOCUS, (WPARAM)hWnd, 0);
    }
 }
 
@@ -106,7 +106,7 @@ IntSendSetFocusMessages(HWND hWndPrev, HWND hWnd)
 {
    if (hWnd)
    {
-      IntSendMessage(hWnd, WM_SETFOCUS, (WPARAM)hWndPrev, 0);
+      IntPostOrSendMessage(hWnd, WM_SETFOCUS, (WPARAM)hWndPrev, 0);
    }
 }
 
@@ -411,7 +411,7 @@ NtUserSetCapture(HWND hWnd)
       }
    }
    hWndPrev = ThreadQueue->CaptureWindow;
-   IntSendMessage(hWndPrev, WM_CAPTURECHANGED, 0, (LPARAM)hWnd);
+   IntPostOrSendMessage(hWndPrev, WM_CAPTURECHANGED, 0, (LPARAM)hWnd);
    IntLockMessageQueue(ThreadQueue);
    ThreadQueue->CaptureWindow = hWnd;
    IntUnLockMessageQueue(ThreadQueue);
diff --git a/reactos/subsys/win32k/ntuser/message.c b/reactos/subsys/win32k/ntuser/message.c
index aaa52f0605a..64ee4e69ea3 100644
--- a/reactos/subsys/win32k/ntuser/message.c
+++ b/reactos/subsys/win32k/ntuser/message.c
@@ -16,7 +16,7 @@
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
-/* $Id: message.c,v 1.56 2004/04/07 21:12:40 gvg Exp $
+/* $Id: message.c,v 1.57 2004/04/13 13:50:31 weiden Exp $
  *
  * COPYRIGHT:        See COPYING in the top level directory
  * PROJECT:          ReactOS kernel
@@ -373,7 +373,7 @@ NtUserPeekMessage(LPMSG UnsafeMsg,
   return Present;
 }
 
-static BOOL STDCALL
+static BOOL FASTCALL
 IntWaitMessage(HWND Wnd,
                 UINT MsgFilterMin,
                 UINT MsgFilterMax)
@@ -651,7 +651,7 @@ MsgMemorySize(PMSGMEMORY MsgMemoryEntry, WPARAM wParam, LPARAM lParam)
     }
 }
 
-static FASTCALL NTSTATUS
+static NTSTATUS FASTCALL
 PackParam(LPARAM *lParamPacked, UINT Msg, WPARAM wParam, LPARAM lParam)
 {
   NCCALCSIZE_PARAMS *UnpackedParams;
@@ -711,7 +711,7 @@ UnpackParam(LPARAM lParamPacked, UINT Msg, WPARAM wParam, LPARAM lParam)
   return STATUS_INVALID_PARAMETER;
 }
 
-LRESULT STDCALL
+LRESULT FASTCALL
 IntSendMessage(HWND hWnd,
                UINT Msg,
                WPARAM wParam,
@@ -725,7 +725,7 @@ IntSendMessage(HWND hWnd,
   return 0;
 }
 
-static LRESULT STDCALL
+static LRESULT FASTCALL
 IntSendMessageTimeoutSingle(HWND hWnd,
                             UINT Msg,
                             WPARAM wParam,
@@ -826,7 +826,7 @@ IntSendMessageTimeoutSingle(HWND hWnd,
   return TRUE;
 }
 
-LRESULT STDCALL
+LRESULT FASTCALL
 IntSendMessageTimeout(HWND hWnd,
                       UINT Msg,
                       WPARAM wParam,
@@ -924,6 +924,47 @@ CopyMsgToKernelMem(MSG *KernelModeMsg, MSG *UserModeMsg)
   return STATUS_SUCCESS;
 }
 
+/* This function posts a message if the destination's message queue belongs to
+   another thread, otherwise it sends the message. It does not support broadcast
+   messages! */
+LRESULT FASTCALL
+IntPostOrSendMessage(HWND hWnd,
+                     UINT Msg,
+                     WPARAM wParam,
+                     LPARAM lParam)
+{
+  LRESULT Result;
+  PWINDOW_OBJECT Window;
+  
+  if(hWnd == HWND_BROADCAST)
+  {
+    return 0;
+  }
+  
+  Window = IntGetWindowObject(hWnd);
+  if(!Window)
+  {
+    SetLastWin32Error(ERROR_INVALID_WINDOW_HANDLE);
+    return 0;
+  }
+  
+  if(Window->MessageQueue != PsGetWin32Thread()->MessageQueue)
+  {
+    Result = NtUserPostMessage(hWnd, Msg, wParam, lParam);
+  }
+  else
+  {
+    if(!IntSendMessageTimeoutSingle(hWnd, Msg, wParam, lParam, SMTO_NORMAL, 0, &Result))
+    {
+      Result = 0;
+    }
+  }
+  
+  IntReleaseWindowObject(Window);
+  
+  return Result;
+}
+
 static NTSTATUS FASTCALL
 CopyMsgToUserMem(MSG *UserModeMsg, MSG *KernelModeMsg)
 {
diff --git a/reactos/subsys/win32k/ntuser/msgqueue.c b/reactos/subsys/win32k/ntuser/msgqueue.c
index 58e18c3e2ed..df0c98b72b4 100644
--- a/reactos/subsys/win32k/ntuser/msgqueue.c
+++ b/reactos/subsys/win32k/ntuser/msgqueue.c
@@ -16,7 +16,7 @@
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
-/* $Id: msgqueue.c,v 1.82 2004/04/09 20:03:19 navaraf Exp $
+/* $Id: msgqueue.c,v 1.83 2004/04/13 13:50:31 weiden Exp $
  *
  * COPYRIGHT:        See COPYING in the top level directory
  * PROJECT:          ReactOS kernel
@@ -682,7 +682,7 @@ MsqPeekHardwareMessage(PUSER_MESSAGE_QUEUE MessageQueue, HWND hWnd,
   return(FALSE);
 }
 
-VOID STDCALL
+VOID FASTCALL
 MsqPostKeyboardMessage(UINT uMsg, WPARAM wParam, LPARAM lParam)
 {
   PUSER_MESSAGE_QUEUE FocusMessageQueue;
@@ -722,7 +722,7 @@ MsqPostKeyboardMessage(UINT uMsg, WPARAM wParam, LPARAM lParam)
   }
 }
 
-VOID STDCALL
+VOID FASTCALL
 MsqPostHotKeyMessage(PVOID Thread, HWND hWnd, WPARAM wParam, LPARAM lParam)
 {
   PWINDOW_OBJECT Window;