SwingSet2: JInternalFrame demo Taskbar isn't refreshed after frame is maximized

SwingSet2: JInternalFrame demo Taskbar isn't refreshed after frame is maximized
Platform: Generic
L&F: All except GTK
Steps to reproduce:
1) Run SwingSet2.jar(Don't maximize the SwingSet2 frame and keep its default size)
2) Now Minimize all the internal frames (which can be minimized).
3) You should see all the internal frames as taskbar icons.
4) Now maximize the main SwingSet2 frame, Notice the task bar icons still
   at there same corrdinates.(Have a look on attached Image
   Taskbar_Unrefreshed.png)
5) Now go to any other demo and come back to Internalframe demo,
   This time Internal frame icons are present at right place i.e. bottom of
   window.
This bug can be reproduced in Tiger also.