When moving components within a container, the entire container is
cleared and the damaged rect is not updated.
 
  Problem:
   This is caused by a bug in AWT. In beginValidate() of
   WComponentPeer.java, a call to g.clearRect() is made. This call
   is in error. It causes unnecessary flashing and redraw, and worse,
   the damaged rectangle is not updated to include the entire
   size of the Component. It is assumed that a full repaint() will
   later be made, and this assumption is in error. Fundamentally,
   laying out components should not cause flashing anyway, as they
   may well end up in the same place.