Make sure that HWND comparisons are always done with full 32-bit
handles.

diff --git a/windows/clipboard.c b/windows/clipboard.c
index 422d71f0..cc321e1 100644
--- a/windows/clipboard.c
+++ b/windows/clipboard.c
@@ -1366,7 +1366,7 @@
     else
 	WARN("hWndViewer is lost\n");
 
-    if( hWnd == hWndViewer ) hWndViewer = WIN_GetFullHandle( hWndNext );
+    if( WIN_GetFullHandle(hWnd) == hWndViewer ) hWndViewer = WIN_GetFullHandle( hWndNext );
 
     return bRet;
 }