I've managed to solve my problem by using kernel 3.0.0-17-generic x86_64 from 11.10, and I've gone a couple days now without any lockup.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/993187 Title: ubuntu 12.04 64bit completely freezes frequently To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/993187/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs