I know my co-worker's suffering from the same issues reported by the Inq here, & he owns an ASUS M2N32-SLI Deluxe Wireless Edition. The random shut-downs have forced him to swap out every component in his system in search of the culprit, & the only thing left is the motherboard. I'd say, though, that since this issue appears to be a cross-manufacturer one, we may be looking at an unstable nForce5 chipset...

"After discussing the matter with several owners of K9N Ultra and K9N Platinum motherboards, both powered by an nForce5 570 chipset - we learned that there are several active problems on the motherboards themselves. All the problems that owners are complaining about result in the same thing: a random shutdown of the system."