I also had this issue after gutsy2hardy update with nvidia card. The gdm login screen had a super high virtual resolution. I remember going trough a lot of trouble getting the desktop resolution ok. Commenting the virtual line in xorg did not work for me. What worked for me was leaving just the resolution mode I use on the modes line, just as did Mariano on comment #7 of the duplicate bug: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/139912/comments/7
I also had this issue after gutsy2hardy update with nvidia card. The gdm login screen had a super high virtual resolution. I remember going trough a lot of trouble getting the desktop resolution ok. Commenting the virtual line in xorg did not work for me. What worked for me was leaving just the resolution mode I use on the modes line, just as did Mariano on comment #7 of the duplicate bug: https:/ /bugs.launchpad .net/ubuntu/ +source/ xorg/+bug/ 139912/ comments/ 7
attached is my xorg