I have a test system: Centos 5.2 on an OQO, that has been hanging hard. I have to unplug it and pull the battery so I can then cold start it. This last time all I did was open a terminal window and SU to root, then start the lastest build of SIP Communicator (which uses JRE 1.6.0_10). I was not even making a test phone call at the time. Oh, and the system only runs IPv6, no v4 addressing. So how do I find out what is causing the hard lockups?