Well, as far as I understood now, it is somehow related to cable plug, but not all the times. Maybe it affects module load or something.
Here is a peace of syslog I have captured before by tailing its output to file before everything hung on kernel 2.6.38-8. I will try to use fwts soon. ** Attachment added: "syslog exert (tail)" https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/727620/+attachment/2115022/+files/syslog.log -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-ati in Ubuntu. https://bugs.launchpad.net/bugs/727620 Title: [Radeon HD 5650 and 5470] Kernel BUG during recovery boot and in normal boot (Hybrid graphics) _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp