I'm running a Core2 Quad, 4 gigs of ram and two 8800GT's in SLI and I'm having the exact same problems you guys are. If it's a memory issue I gotta believe it's a memory leak on Firaxis's end or the mod I'm using is utilizing way more resources than I think. I can't imagine this machine having trouble running this game even with huge or larger maps. Everytime my turn ends another civ tries to contact me and the game crashes...everytime that particular turn ends and the communication video tries to load I get the "this game has cause...yadda yadda yadda" error and it crashes. I AM running a larger than huge map..140 x 84 with the Wolfshanze mod. Maybe my problem is with the mod? In vanilla I have no trouble loading much larger maps but with this mod that particular size is the largest that I can load..all others crash. Just how much ram would one need to run a mod like that on truly gargantuan sized maps?
Edit>> I'm running XP pro with SP3
Edit>> I'm running XP pro with SP3