--- a/src/qt3support/widgets/q3dockarea.cpp	Tue Jan 26 12:42:25 2010 +0200
+++ b/src/qt3support/widgets/q3dockarea.cpp	Tue Feb 02 00:43:10 2010 +0200
@@ -1019,6 +1019,7 @@
         if (!keepNewLines)
             dw->setNewLine(false);
     }
+    layout->invalidate();
     layout->activate();
 }
 
@@ -1138,7 +1139,7 @@
 {
     if (accept)
         forbiddenWidgets.removeAll(dw);
-    else if (forbiddenWidgets.contains(dw))
+    else if (!forbiddenWidgets.contains(dw))
         forbiddenWidgets.append(dw);
 }