I was experiencing exactly the same issue, which I reported there: https://launchpad.net/distros/ubuntu/+source/update-manager/+bug/52668/
In the end I marked my bug report as a duplicate of: https://launchpad.net/distros/ubuntu/+source/nvidia-glx/+bug/49834 -- crashes when one of the resources is not available https://launchpad.net/bugs/52658 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
