I saw someone else post something about this but mine is a little different.
FSD 2.0b Rev 2342
I really only play one game right now (COD Black Ops - system link Zombies). We've been playing almost every night for 2 months and the problem just started showing up a few days ago. Nothing was done to the system. The game was on an external USB drive so I started playing off a backup DVD but it still crashed. There are no systemupdate folders on the USB drive.