In the Kasserine Pass mission as i'm making my way through the bunker to destroy the muntions dump, I get so far then the game cuts out.

I'm walking down a corrider, about to enter the second machine nest when the game just cuts back to the start screen (with the load/save game, controls, credits etc) It's as if I've hit escape but I haven't. I reload my game and the same thing always happens

Please Help
AY