I've been experimenting with xorg.conf and I now know the setting that makes the difference.
Basically the default xorg.conf auto-created on booting the live cd only contains mode definitions in the "Screen" section for "1024x768", "800x600", and "640x480". But the Gnome "Screen Resolution" tool lists these plus others all the way up to my monitor's max res of "1440x900" (screen shot attached). Trying to change above "1024x768" to these other res's causes the screen corruption. I ran dpkg-reconfigure for xserver-xorg. The resulting xorg.conf allowed me to change the resolution perfectly. So I compared the differences one by one and the one which fixes the problem is to explicitly add a mode definition for "1440x900". Then after restarting Xorg it goes into "1440x900" by default, and can successfully switch to any of the other resolutions between the original "1024x768" and "1440x900" listed in the Gnome "Screen Resolution" tool. I've attached my working xorg.conf, and Xorg.log labelled 'good' and the default generated version and its related Xorg.log labelled 'bad'. I've also made diffs between both the logs and xorg.confs to highlight the differences. I've not got a machine which I can justify installing Feisty to yet so this is still just from testing with the live CD. Today I've tested on the post-beta snapshot 2007-03-27 and this problem still exists. I'm not sure if this should be considered an xserver-xorg-video-ati, or casper, or X issue. -- Corrupt screen when switching resolution https://launchpad.net/bugs/84158 -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
