Comment 27 for bug 5801

I have a nvidia GeForce 6200 card and am using the nvidia-glx package. I was having the same/similar problem on my desktop, (this problem occured after the upgrade from 6.06 to 6.10, now i have 7.04 herd 4 and the problem still exists.) The resolution was set to 1600*1200 but the actual resolution was 1024*768 witch was pretty annoying. I bumped in to the following solution

Open your /etc/X11/xorg.conf search for the section device and ad Option "useEDID" "False" and restart your xserver (ctrl+alt+backspace)

It might work in this case. I looked to the other bugs listed above and none of the offered solutions worked