Java will not run unless I do the following hack which will set the environment variable system wide.

vi /etc/environment

PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games"
LANG="en_AU.UTF-8"
LANGUAGE="en_AU:en"
LIBXCB_ALLOW_SLOPPY_LOCK=true

add the LIBXCB... line, save and then log out and back in and you should be able to run java apps.

To test run the following (edit to taste if you have sun 5)
/usr/lib/jvm/java-6-sun/bin/ControlPanel

You should see