Denominus: I get it as well with my 5970 and the 11.5b hotfix. The hotfix gave me greatly improved FPS, but completely broke the lighting. Its at its worst indoors.
Its a Crossfire issue, but considering the 11.5b hotfix was supposed to fix Crossfire with TW2 I am getting quite aggravated with AMD at this point. The game has been out some time now and I really just want to have a good playthrough.
I have been a long time ATI user and had most of their flagship cards, but my next card is definitely going to be from NVidia.
There are crossfire issues with a lot of games in the first weeks. Bad Company 2, Brink, Crysis 2. It's just too much.
My next card will still be from amd probably, but I will never buy a crossfire card again.