Well, just ran fatw until I got bored (200 turns) on -ai with autosave set to true and no CTDs at all...so no problem there.

I've played with some quick save files sent to me and, as far as I can tell, I seem to get a ctd on the ai turn when I have fog of war on (I never have it on so I would never see any fow-related problem)....so...what would cause it to ctd with fow on, but not with it off?