I have a 6950 on route today. Will report back here.
So what client are you running / what OS and what drivers versions etc?
Cheers!
Please, don't follow that article's directions. Those are for flashing a 6970 bios into a 6950 card; such procedure may permanently damage your card, as Grinder writes warns in his post. EDIT: Grinder's guide is the new, safer method.