XGL causes dual-monitor breakage after upgrading from Feisty to Gutsy

[CTW]

After upgrading from Feisty to Gutsy my dual monitor setup stopped working. I'm using an HP Pavilion dv1000 laptop with the intel centrino graphics chipset (i810 driver) and I have an external Lenovo ThinkVision monitor hooked up. The attached xorg.conf worked in Feisty (and Edgy), but now in gutsy, it is no longer usable. The login screen displays fine (in both KDM and GDM) but when KDE or Gnome are loaded, I can only see the background image, but no desktop (however, the startup sound for KDE or Gnome plays as if it was successfully started). Keyboard shortcuts or right clicking with the mouse have no effect. I can load failsafe, start kwin from Konsole and drag windows around both screens as desired. Given this fact and the fact that the same xorg.conf worked in previous versions of Ubuntu, it seems that the desktop environments are somehow involved in the problem. I tried deleting the .kde folder as suggested here https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/67985 , but no luck. Any help would be appreciated as this bug seriously impedes the usability of Gutsy for me.

[CTW (ctw)]

The xorg.conf file that worked in Feisty.

[CTW (ctw)]

I've experimented some more to help pinpoint the problem. The problem persists in xfce and when xserver-xorg-video-intel is removed and the xserver-xorg-video-i810 package is downgraded to the Feisty version. Thus so the dual screen setup works in Feisty and only in Failsafe mode (even with kwin loaded) in Gutsy. Please let me know if any other information would be helpful.

[CTW (ctw)]

When using the integrated LCD monitor only (e.g., by commenting out the xinerama line in the above xorg.conf file) I have also noticed that the display quality is not as good as it could be. Scrolling is choppier than what I'm used to and certain GUI elements flicker when the mouse passes over them. Again, none of this was a problem in Feisty.

[CTW (ctw)]

I have solved all problems by simply uninstalling xserver-xgl. This bug is therefore misclassified. Even when deleting the xorg.conf file I had a lot of display issues when xserver-xgl was installed. The display was very slow to update and the fonts were rendered very badly. By running apt-get remove xserver-xgl all those problems disappeared and the above xorg.conf file works just as in Feisty. It seems that xserver-xgl got automatically installed during the gutsy update and that this caused the problem. It'd be great if this could somehow be avoided as it took me a lot of time to pinpoint the source of the problem.

[CTW (ctw)]

Other people in the Ubuntu Forums report similar problems, e.g.: http://ubuntuforums.org/showthread.php?t=579762

[unggnu (unggnu)]

Could you please recheck it with Gutsy Final Live CD? In Gutsy i810 driver is deprecated and intel driver is used instead.
Xinerama isn't supported anymore through new Intel driver since xrandr is used instead. Isn't it possible that you have Xgl installed before. I guess there would plenty much more bug reports if Gutsy upgrade would install Xgl automatically.

[CTW (ctw)]

It is possible that Xgl was installed before. I don't remember installing it, but I have been upgrading for several versions (rather than doing a fresh install). However, if it was installed, it didn't cause problems in the past. Perhaps it should be uninstalled with the intel driver update?

[unggnu (unggnu)]

Does it work without Xinerama and XGL for you?

[unggnu (unggnu)]

I am closing this bug report because it lacks the information we need to investigate the problem. Feel free to open it again if you still experience the problem with the new Intel driver, AIGLX and xrandr.

[CTW (ctw)]

Sorry for not replying earlier. Everything works without XGL, even with Xinerama.