OpenSuse 11.1 - machine randomly shuts down

I’ve recently installed OpenSuse 11.1 on a Dual Opteron machine. Everything seems to be fine except that the machine will randomly shutdown. I’ve searched all the logs and I can’t find anything fatal which would indicate the cause of the shutdown. There are some messages from the smart daemon but its for a non system hard drive.

At this point, I’m not sure what else to check. Could this be a power optimization issue? Is the machine shutting down because of some power setting?

Previously I has this machine running Sles 10 reliably with very good uptimes.

Any pointers to what I should look at would really be helpful.