Well I have determined that for me this problem is caused by linux kernel 3.5.0-3 (pulled in via linux-image-generic) which was installed on my system via xorg-edgers ppa. I removed this and went back to the generic precise kernel which is currently 3.2.0-26 and my lockups have gone. I am still using xorg-edgers ppa, just back-graded that kernel version.
-- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-nouveau in Ubuntu. https://bugs.launchpad.net/bugs/1012916 Title: [nouveau] 12.04 Unity 3d hard freezes To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/1012916/+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
