Just something to try, but please consider it because I've been there, and this was my solution, one I never thought would even be possible. If your monitor allows it, try swapping out the monitor cable.
I was experiencing ghosting (like a double shadow of everything a little to the right of each object), and it frustrated me to no end. Made 2D look horrible, especially at high resolutions (was in 3D too but VERY hard to see there).
Replaced my what-I-thought-was high-quality gold-connector monitor cable with an old (albeit thicker) regular one and whala, picture cleared up completely! So now I have a new (DVI to VGA) cable on order that I hope will fix this (one I'm using will work for the time being, but it's not in great shape either - lol).
I almost didn't try this. I ran 1600 x 1200 32 bit on my old Ti4600 with the cable without any problem, but the 6800 just doesn't like it. (I even had a brand new one...same model cable...lying around and tried it - same result...it's something about the cable or shielding or something.)
Anyways, if you haven't tried it and can (I know some monitor cables are built in), I would...
Good luck. Know this is frustrating.