Comment 21 for bug 195721

I'm getting the same problem as well. None of the solutions I've tried have seemed to be permanent. System specs and debugging attempts are here:

http://ubuntuforums.org/showthread.php?p=4817281#post4817281

Nvidia card, and the whole system freezes about 4 seconds after hitting return on my password. Mouse stops responding, and only hard reset will work. After re-installing from scratch and removing what I thought might be a bad memory module the system was fine for days. Then, tonight, I enabled the security updates, did them all, and rebooted, and now it's back in the same
failure mode as before. I'd love to know which package changed to cause the problem.