PIT:GTK L&F SwingSet2: Task bar not shown JInternalFrame demo

JInternalFrame Demo not showing taskbar when switched back from someother demo
Steps to reproduce:
- Open SwingSet2
- Change to GTK Look And Feel.
- Notice there is taskbar present on JInternal frame demo with six icons.
- Now switch to JProgress bar demo ( Or anyother demo).
- Now switch back to JInternal frame demo. Now taskbar is not visible in JInternalFrame demo.
- Now click again on JInternal frame demo toolbar button. This will make taskbar visible.
JDK: Tiger PIT 10.OCT.2003 and Tiger PIT 14.OCT.2003
All OS.