Bug 23398

Forwarding this bug from Ubuntu reporter Ronald McCollam:
http://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/412492

[Problem]
X flickers wildly whenever any object on-screen updates when display is set to its native resolution (1440x900).

[Original Description]
After dist-upgrading today on , X flickers and is unusable any time any object on the screen is painted.  Opening the main menu from the panel causes the entire screen to flicker for around a second.  Switching desktops or opening/closing/moving a window causes similar behavior.

The flickering appears to be parts of the screen being briefly updated in the wrong place; it's much like a jerky shift of halves or quarters of the screen to the wrong position very briefly.

Deactivating compiz does not seem to change this behavior.

Further testing reveals that this appears to affect my display only when set to its native resolution (1440x900). Changing to another resolution, e.g. 1024x768, makes this problem go away.

The graphics controller is:
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML Express Integrated Graphics Controller (rev 03)

I've attached a video of an example of the effect captured from my phone.  (I apologize for the poor quality of the video, but it gives a sample of the effect.)  In the video I have opened the main menu and then switched to another virtual desktop.  However the same effect happens during nearly any screen update -- every character I type right now in this bug report is causing a brief nauseating flash.

Architecture: amd64
Date: Wed Aug 12 08:30:34 2009
DistroRelease: Ubuntu 9.10
MachineType: Dell Inc. MXC061
Package: xorg 1:7.4+3ubuntu5
ProcCmdLine: root=UUID=4e88e4b9-d7a1-4e91-8105-ecfbf01429a9 ro quiet splash
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8ProcVersionSignature: Ubuntu 2.6.31-5.24-generic
RelatedPackageVersions:
 xserver-xorg 1:7.4+3ubuntu5
 libgl1-mesa-glx 7.5-1ubuntu1
 libdrm2 2.4.12-1ubuntu1
 xserver-xorg-video-intel 2:2.8.0-0ubuntu2
 xserver-xorg-video-ati 1:6.12.99+git20090629.f39cafc5-0ubuntu5
SourcePackage: xorg
Uname: Linux 2.6.31-5-generic x86_64
dmi.bios.date: 04/02/2007
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A10
dmi.board.name: 0MG532
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA10:bd04/02/2007:svnDellInc.:pnMXC061:pvr:rvnDellInc.:rn0MG532:rvr:cvnDellInc.:ct8:cvr:
dmi.product.name: MXC061
dmi.sys.vendor: Dell Inc.
system: architecture:       x86_64kernel:             2.6.31-5-generic