I've seen this error a few times in the last week. It sounds like a kernel problem to me.
Googling it gives a few hits, but nothing specific for a fix, other than possible new kernel fixes. AU has some hits, but also no specific fixes that I've seen.
It locks up the machine. I only have 4 or so apps running... Firefox, Thunderbird, Liferea, and KeePass. It just happened when I tried to restart the computer.
Anybody have any idea what this is about?