Oh, my mistake. I've got the latest patch, v2.00.28. My system profile information IS on my profile however.
As far as I can tell I've patched it correctly. I put both patches in the game folder after I installed it, and applied the 2.00.00 patch then the 2.00.28 patch, and it said both were OK.
I read somewhere that there was a problem with a crash because the ammo counts for some weapons were wrong. I'm thinking maybe that's the problem.
I also thoght that maybe the game wasn't loading the weapons correctly, but I tried loading the weapon models using the BCStudio tool, and it shows them fine, so it can't be that.
If you guys can fix this you have my eternal gratitude