I have two 6950's in crossfire with the unlocked shader in bios. Oced them both to 880/1350. 20% power control settings. Both cards are watercooled and temps are fine. Using a corsair 1000W PSU. Im using a asus 27" display under HDMI. For some reason as soon as i enter the battle in BFBC2 screen goes black but i can hear the sound for a while then stops. Go into any other game and its fine. anyone have any suggestions?.