Artifacting?

[Graphxproblems]

I just got a new XFX 1GB Radeon HD 4870. All games I've tried so far are running great on the highest settings w/ AA and AF at 1920x1080. However, I'm getting these black lines and artifacts running across the screen in Crysis (it seems to affect shadows most noticably).

I had the exact same problem with the Crossfire X1950 XTX's I had previously, and am really surprised that it's persisting with a new card. The 4870 is running very quietly and at a low temperature, so heat isn't the issue. Crysis' performance is fine as well. I'm running the 9.11 drivers. Here are the rest of my system specs:

Core 2 Duo OCed to 3.22 GHz
3GB RAM
700 watt PSU
Intel D975XBX mobo

What would be causing the artifacts? Thanks.

 

[Graphxproblems]

After some experimenting, it seems that the issue only occurs with AA enabled.

 

[shansoft]

black line? can you take a sreenshot?

 

[Graphxproblems]

black line? can you take a sreenshot?

I have taken a screenshot, but I cannot paste it in here for some reason. The corruption is a flickering haze of translucent black dots on the screen. The corruption seems to remove the shadows from character models as well. Installing the hotfix did nothing.