Kernel tainted message

Having received an message about my kernel being tainted I did a dmesg | -i grep taint and got

[13247.190943] Pid: 1070, comm: java Tainted: G C O 3.6.7-4.fc17.i686.PAE #1

so I presume this was caused by Java but what or how I have no idea. Has anyone else seen this? Is there any more I can get to find out why?

Stuart