Shadows not displaying correctly

[Daiyuki]

Heya, my problem seems to be with how shadows are rendered at a distance. In many areas I get the graphical problem in the attached picture. I believe it may be my specific setup, as others do not see the glitch, which I can only describe as succeeding circles of pixelated dark green. I assume it is supposed to be the shadows getting darker and darker, but it is not working. The shadows very close up are fine, object shadows are fine, it is just that effect that is giving me trouble, and since shadows are an integral part of the game, I have stopped playing, because the greenish darkness is bothering me =p. Other games do not give me this issue, so I do not understand where this problem comes from. Metro 2033, for example, is running perfectly and darkness is a huge aspect of that as well. Possibly related is the smoke/fog effects looking quite bad most of the time, even the smoke to the right of the screen in the main menu, it gets that same "pixelated" effect when fading in and out, but doesn't seem to change colors at all.

Windows 7 64-bit
GTX 470 stock speeds
Core i7 930 OC'd to 3.8ghz
12GB RAM
Latest drivers
Version 1.0.0.0 of the game
With various settings the problem persists, from no post-effects to everything maxed, except SSAO samples because that just kills my GPU, fullscreen and windowed.. I just don't understand.

Any help is greatly appreciated!