1) Post debug.err, or the last few lines of it, after a crash, before going back into the game (as that creates a new/current debug.err which overwrites the old one). (Debug.err is in the appropriate folder in your My Games folder in My Documents.)
2) Download
SmartException.
3) Are you running windowed mode or fullscreen? Try the other one and report back.
4) Did you say SLI? I seem to remember SLI not working with GCII, but I can't recall offhand. I'll look around, but someone else will probably get to commenting on it before I do.
