Well can't rule out a defective card.
Catalyst settings should be at default. In the gaming options, make sure everything is on "use application settings". At the bottom, check Triple Buffering and apply. Now try gaming. Also, you should try Vsync off as well, especially if you're under 60fps.
Ill try those options after work. This is really annoying :\
I am going to download the benchmark utility (I forget what it is called 3DMark or something) and run that to see what my score is.