this is a great game, but it sometimes freeze during the campaign. it often occured in dialogue scene with NPC. when it happened, the sound of video card fan stopped and restart after few seconds.then the game resume to normal, but soon it would totally froze up. so far no such problem in RTS. i tried disabling the crossfire, it seemed solved the problem. but i really hope this issue will be paid attention and fixed, so i could play the game with two video card.