crysis crashes to windows.

Hey all,
I modified the multiplayer.cfg file in the crysis directory to enable motion blur in multiplayer and well it works...for a bout 2-5 minutes and then the game crashes back to windows anyone else had this problem? I've heard of several cases and they were really inconclusive as to getting it to run without crashing, hopefully someone on here can shed some light on this for me I've updated to the latest BETA nvidia drivers, specs are listed below.
running windows xp pro
thanks alot!