On my desktop machine, I have a dual monitor setup with 2 19" monitors and an ATI Radeon graphic card running each monitor at 1152x864. This setup has worked flawlessly for me for a couple of years. Recently, though, my primary monitor has been acting up. When I first boot up, I need to move my mouse, which then "scrolls" the viewable area. It's like I have a virtual desktop with the size of my monitor set too small for the resolution at which I'm running.
I dug around on the Display Properties' Advanced setup and went to my video card's control center. There, I noticed the EDID settings were claiming the maximum resolution of the monitor was 1024x768. That would explain this behavior. I disabled EDID for the problem monitor and set the value to the proper resolution (1600x1200). Everything is working great again.
Disclaimer The opinions expressed herein are my own personal opinions and do not represent my employer's view in any way.