I have test which loops through all the GraphicsDevices available on the platform. For each GD, it obtains all the GCs and loops through all the GCs and does the following -

- Create a JFrame specific to the GC
- Add a few swing components to it
- Push the JFrame to fullscreen mode
- Restore the frame to normal mode
- Dispose the frame

This is done repeatedly for all the GCS and for all the GDs as well. After a couple of loops, this throws a NullPointerException at the setFullScreenWindow(null) method call on SuSE10.0. This works fine on Win32. Not sure if this is specific to the video card. I have ATI Radeon 9600 installed on this machine with the latest ATI driver - 8.34.8 and I have turned on dual-head. 

Here is the exception-
Exception in thread "main" java.lang.NullPointerException
at sun.awt.image.VolatileSurfaceManager.displayChanged(VolatileSurfaceManager.java:310)
at sun.awt.SunDisplayChanger.notifyListeners(SunDisplayChanger.java:102)        
at sun.awt.X11GraphicsEnvironment.displayChanged(X11GraphicsEnvironment.java:1068)
at sun.awt.X11GraphicsDevice.setDisplayMode(X11GraphicsDevice.java:380)
at sun.awt.X11GraphicsDevice.setFullScreenWindow(X11GraphicsDevice.java:284)
at SwingMultiFullScreenTest.startTest(SwingMultiFullScreenTest.java:72)
at SwingMultiFullScreenTest.main(SwingMultiFullScreenTest.java:83)

I am able to reproduce this since JDK6-b59d and on JDK7 as well. It works fine on JDK6-b40. 

I have attached a sample test. Execute the sample test and you will see the above exception after few loops.