I am getting very, VERY annoyed at this. I tried the above but it doesn't really work. I might have to get an nVidia card just so I can play this game right. :|

I have the same problem, 9 out of 10 away mission my gameclient crashes...i got a Hd5850 and im not gonna buy a nvidia card just for this game. If this problem prolongs after beta i wont pay for this game. However since its still beta it is most likely going to be fixed.

This solution worked for me. I'm running two ATI 4850s in crossfire. Reset to default. Then changed resolution to 1680 x 1050, and had to turn vertical sync back on. Then I did the /maxfps 60 thing. Was able to complete the mission with no problems.

I am having this issue also,
I tested my Video card and ram. I did find one of my RAM sticks was fried.
the game still crash without any error to desktop.

ATI users:

Shut off Post-Processing and Dynamic Shadows. The game won't look as good, I know, but the crashes stopped.

Turning down the graphic should really not be the ultimate solution to this problem, but as a temporary fix it's okay, at least for me, i know my computer is more than able to run this game at full, so i would rather want this bug/problem fixed in another way.