Just what the title says.

I managed to play the game smoothly untill the supertanker mission. Now, when I get there as soon as the game loads, the screen freezes for about 10 seconds and then the monitor goes into power saving down and I can't turn it on. I can't ctrl-alt-del to kill the process, the whole computer becomes unrespondable. This is by far the worse issue I have had with any game, it makes troubleshooting virtually impossible.

My specs are:
XP SP2
Abit AN8 SLi
AMD Athlon X2 4200+
ATI HD 3870
2GB DDR (Dual channel)
Audigy 4
Corsair VX550W

It's not a problem with my GPU, PSU or anything as I can run more demanding games like Crysis, COD4, perfectly with no crashing whatsoever for a few hours.

Anyone else had any similar issues?