I'm running Xubuntu (linux) and as mentioned before I installed the drivers via the public repos. If I'm only mining on one GPU with two OpenCL instances then wouldn't that be a configuration issue in cgminer and not my driver?

I'll see if I can find another linux driver but honestly I don't think that's the issue. I'll also try with Windows 7 just to make sure one of my cards isn't defective or something.

Any other thoughts folks? I was under the impression a lot more people were using linux on their miners but it seems like most of the folks who replied to this thread are using windows.