black horizontal bars/glitching on display in bottom right hand corner of screen

[willie_wang]

black horizontal bars appear in bottom right hand corner of the display. see attached picture. although all windows below the glitching are affected, the mouse cursor strangely floats over these black bars unaffected. the black bars did not show on the screen print, so i painted them over the print in GIMP so you see what they look like.

this problem not only occurred in ubuntu, but also xubuntu - 32bit and 64bit versions.

i managed to solve this problem by adding a line to my xorg.conf in the Device section:

 Option "XAANoOffscreenPixmaps" "true"

so my full Device section in my xorg.conf looks like this:

Section "Device"
 Identifier "aticonfig-Device[0]"
 Boardname "ati"
 Option "XAANoOffscreenPixmaps" "true"
 Busid "PCI:1:0:0"
 Driver "fglrx"
 Screen 0
EndSection

Several people seem to have come across this bug. It may have something to do with the ATI proprietary driver, as I have always used this driver (7.11).

Here is the link to the forum post where other people are suffering a similar problem. http://ubuntuforums.org/showthread.php?t=614410

Output: uname -a
Linux wil-notebook 2.6.22-14-generic #1 SMP Sun Oct 14 23:05:12 GMT 2007 i686 GNU/Linux

Is there any other information you guys need?

[John Rose (johnaaronrose)]

Same issue on Dell Inspiron 1501 using ati driver fglrx under gutsy. Ati driver installed using Envy. xorg.conf attached.

Occurs intermittently. Not able to identify conditions yet.

[willie_wang (wil-hoang)]

you need to add the following line to your xorg.conf in the Device section:

 Option "XAANoOffscreenPixmaps" "true"

read original bug post for more info.

[Tom Norback (tomnorback)]

Same bug here with Gutsy on an AMD64, fglrx, ATI 1300 graphics board. Happens nearly every day. Haven't noticed exactly what triggers it. Restarting X clears the corruption.
Thanks Wille for the XAANoOffscreenPixmaps suggestion. I've edited it into xorg.conf. I hope it works.

[John Rose (johnaaronrose)]

Hardy upgrade has solved this for me.

[Timo Aaltonen (tjaalton)]

The xserver in hardy has that option set, so this bug is fixed.

[Dominik Wujastyk (wujastyk)]

Ubuntu 10.10 with fglrx, and I *still* had the screen corruption with horizontal shear/stripes. The above fix works for me. Thanks!