I recently purchased a 23" 1080P monitor after using a 19" TV which used 1680x1050. The issue I'm having is a strange one indeed.
The television was connected to my comp via HDMI (1680x1050) and now, after switching to the 1080P monitor, it seems that my screen is still scaling to fit the old TV. There are black borders about an inch long on every side in 1080p, but not when I switch to 1680x1050. Still in 1680, the resolution seems blurry, everything looks highly pixelated. I borrowed a DVI cable from my brother to see if it fixed the problem, and sure enough the problem is completely resolved... Crystal clear in 1080 and high visual fidelity.
The thing is, I want to run eyefinity on a 7950 HD, which only has 1 DVI port. The HDMI/Displayports are all having this scaling issue and I cannot seem to figure it out.
So far I've tried completely uninstalling all ATI affiliated software (restarting) then installing the newest catalyst along with the entire software suite to no avail.