Black Screen crash

[GinTenshi 0]

And first it not like everyone elses where there is still sound and everyting.

 

So usualy the first 2-4 times I load up a server I start running around and usualy 2 minutes after my game will stop receiving all commands and either spin, stop or keep with the last command I gave and 20 seconds after that the game will crash to a black screen. no sound no movement nothing, full on crash. I updated my vid driver thinking that was it, worked for a while (I think or it was just liking me at the time.) and that didnt help.

 

AMD xII 645 @ 3.1 Ghz

4gb Ram

and a Nvidia 8400GS

 

any thoughts?