Openjdk-6 crashes when notification apears with minecraft on fullscreen mode

[Woody]

Steps to replicate problem:
Run minecraft using openjdk6 ( I used the command java -jar /home/myusername/.minecraft/minecraft.jar). Push f11 to fullscreen minecraft and make a notfication apear (e.g change your volume level).

What happens:
All window borders disapear, unity dock disapears, I'm left with an unusable desktop. I have to restart X to get it back (ctrl+alt+prt scn+k). Sometimes Unity dock and widow borders stay. Often the firefox dropdown menu of the url bar will not display properly after this crash happens.
Also I had vlc running when the crash happens, I maximimse vlc, the window animation happens but vlc won't show up. The window focus will have changed to vlc.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: openjdk-6-jre-headless 6b24-1.11.1-4ubuntu3
ProcVersionSignature: Ubuntu 3.2.0-25.40-generic 3.2.18
Uname: Linux 3.2.0-25-generic x86_64
ApportVersion: 2.0.1-0ubuntu8
Architecture: amd64
Date: Thu Jun 28 09:33:43 2012
ExecutablePath: /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta amd64 (20120301)
LocalLibraries: /home/jotham/.minecraft/bin/natives/libjinput-linux64.so /home/jotham/.minecraft/bin/natives/libopenal64.so /home/jotham/.minecraft/bin/natives/liblwjgl64.so
ProcEnviron:
 LANGUAGE=en_NZ:en
 PATH=(custom, no user)
 LANG=en_NZ.UTF-8
 SHELL=/bin/bash
SourcePackage: openjdk-6
UpgradeStatus: No upgrade log present (probably fresh install)