I have a very odd problem that I have never came across before with a video card.
The card was working fine for awhile since I have gotten it from a friend until recently. The problem that occurs is when I go to open any games up they do not scale to fit my entire monitor. My monitors native resolution is 1600x1200 and is perfectly fine on my windows desktop. When I open Call of Duty 4 the game will start the visible area at the bottom right and scale the picture up to the center but will not fit the whole screen unless ran in 800x600. When I tried running Counter Strike: Source the screen would be centered but still be scaled down and would never cover the entire screen.
I have tried different drivers for the video card thinking that that could be the problem. This did not help at all though.
More about6800 ultra issue
Have u tried using the picture adjustment on the monitor?
If you have a CRT go under your monitor options and adjust the size and positioning... it changes with each resolution. If you have a LCD run it at its native res. For a CRT the size will be in the monitor's options.