I don't think this is a mutter problem, as Unity is affected as well and compiz is the compositor in that case. I'll file this against the kernel since its a hard lockup that seems related to your graphics card, though X may be at fault as well since nouveau worsens the crash. Could you please run the following command in a terminal (from a session that works): apport-collect 899511
That will add additional system information and hopefully some information related to the crash to this report, which the kernel team will need. ** Package changed: mutter (Ubuntu) => linux (Ubuntu) ** Changed in: linux (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/899511 Title: hard crash on ION2 graphics chipsets To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/899511/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs