Out of curiosity I tried the latest mainline kernel from http://kernel.ubuntu.com/~kernel-ppa/mainline/ and it dose the same thing.
** Tags added: kernel-bug-exists-upstream -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/961823 Title: System locks on boot To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/961823/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs