Well, I have a similar problem and dunno if it's related. I experience flickering on some textures, mainly on urban areas and trees. The effect was not as noticeable in beta 4 than the release version.
I've been doing some tests with AA settings and have determined that flickering dissapears enabling super-sampling anti-aliasing and forcing AA via AMD CCC. Obviously, this is not bearable FPS wise even on my HD6950, but hope it could help to narrow the problem.
I'll try to record two videos, one with the flickering and one without for you to see the difference. Also, if this is not the correct thread, let me know.