You could also try a reinstalling your current Catalyst drivers and/or updating to the latest ones. It's possible the card and/or certain features aren't installed properly.
Secondly, try looking at the rear PCB side of the card to see if there are any LED's lit up on it. This would signal a problem with the card. Although this thread from the XS forums is a bit old, it's relevant. You might have a dud card in need of replacement.
Secondly, try looking at the rear PCB side of the card to see if there are any LED's lit up on it. This would signal a problem with the card. Although this thread from the XS forums is a bit old, it's relevant. You might have a dud card in need of replacement.