diff '--width=140' -dru xfwm4-4.10.0/src/focus.c xfwm4-4.10.0-patched//src/focus.c
--- xfwm4-4.10.0/src/focus.c	2012-04-28 22:56:34.000000000 +0200
+++ xfwm4-4.10.0-patched//src/focus.c	2012-06-22 20:32:36.750541528 +0200
@@ -475,7 +475,7 @@
 void
 clientUpdateFocus (ScreenInfo *screen_info, Client * c, unsigned short flags)
 {
-    Client *c2;
+    Client *c2, *prev_top;
 
     TRACE ("entering clientUpdateFocus");
 
@@ -495,9 +495,16 @@
     }
 
     client_focus = c;
-    if (c2)
+
+    prev_top = screen_info->windows_stack->data;
+    if (prev_top != c)
+    {
+        clientAdjustFullscreenLayer (prev_top, FALSE);
+        frameQueueDraw (prev_top, FALSE);
+        clientUpdateOpacity (prev_top);
+    }
+    if (c2 && c2 != prev_top)
     {
-        clientAdjustFullscreenLayer (c2, FALSE);
         frameQueueDraw (c2, FALSE);
         clientUpdateOpacity (c2);
     }