Well I tried disabling the "glass" look and its still there. The taskbar hasnt been on autohide, it is set to small icons but even if its set to large it still has a little blur beneath it! This is why I was confused by the issue haha!
I suppose it could just be the RC coming into play on lower end hardware :P
 well the setting (after playing with alot of them) that fixes it is Enable Desktop Composition. It needed to be disabled. Doesn't look as good, but i guess thats a minor price to pay XD