Using java web start and the provided example app you should notice a problem
with the preferred size of the window. When the app comes up a red box
should surround the components in the split pane to show correct preferred
size. When resized to the smallest bounds you should see only the blue box.
The preferred size is correct under Linux, but not under Windows. This may
have to do with the fact that the JWS warning is added to the top of the window
under Linux and below under Windows.

http://javaweb.sfbay/~kwalrath/tutorial/uiswing/components/example-1dot4/SplitPaneDividerDemo.jnlp