I did what you said, lowered the textures from high to medium, AA to 4 instead of 8, left hdr on etc...and I narrowed it down. i can leave everything on medium-high, hdr on, when i lower textures to medium the dark rectangles are replaced by beautifully drawn clouds. the dark rectangles also result in a massive fps hit. as a reminder, I have to nvidia 9800GTX+ 1 gb video cards dcs.zip