I've had this issue ever since CS4 came out and I've gone through a large amount of different drivers for my current card (4870x2). I had the same problem with an x1950 Pro before I rebuilt my computer. I'm guessing it's an ATI problem but I wonder if anyone's run into it or managed to fix it.
What I'm talking about is the line through the bar at the top and the fucked up minimize/maximize/close icons. It's something stupid but it bugs me I haven't been able to find a solution. Picture below:
Spoiler: show
XI Wiki


