I got the backtrace, here it is. I also have the Apport report file if you want it.
** Attachment added: "Backtrace" https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1280892/+attachment/3990300/+files/Backtrace.txt -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg in Ubuntu. https://bugs.launchpad.net/bugs/1280892 Title: 1002:4b4b Intermittent crashes of Xserver due to video driver To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1280892/+subscriptions _______________________________________________ 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
