Created attachment 28719 [details]
Screenshot.png

Forwarding this bug from Ubuntu reporter Matteo Gazzoni:
http://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/410766

[Problem]
Corruption on pixelmator.com when using KMS (see screenshot)

[Original Description]
karmic alpha 3, all updates + ati kms and kernel from here:
https://edge.launchpad.net/~ubuntu-x-swat/+archive/kms

Compiz is slightly slower, but not unusable.
Scrolling is slow.
Firefox InfoBar animation (the yellow bar which slides down for pop-ups, passwords etc) is jerky.
Video playback seems ok.
Pixelmator.com shows mis-rendered graphics (see screen attached).

Architecture: amd64
Date: Sat Aug  8 18:46:34 2009
DistroRelease: Ubuntu 9.10
MachineType: Apple Computer, Inc. iMac5,1
Package: xorg 1:7.4+3ubuntu5
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-6-generic root=UUID=ab9b0dcf-cd9b-473a-865f-c9ba6d726a6b ro quiet splash
ProcEnviron:
 LANG=en_US.UTF-8ProcVersionSignature: Ubuntu 2.6.31-6.25~radeon2-generic
RelatedPackageVersions:
 xserver-xorg 1:7.4+3ubuntu5
 libgl1-mesa-glx 7.6.0~git20090805.ac3de85e-0ubuntu1
 libdrm2 2.4.12+git20090806.d74c67fb-0ubuntu1
 xserver-xorg-video-intel 2:2.8.0-0ubuntu2
 xserver-xorg-video-ati 1:6.12.99+git20090805.bd03977e-0ubuntu2
SourcePackage: xorg
Uname: Linux 2.6.31-6-generic x86_64
XorgConf: Error: [Errno 2] No such file or directory: '/etc/X11/xorg.conf'
dmi.bios.date: 06/27/07
dmi.bios.vendor: Apple Computer, Inc.
dmi.bios.version: IM51.88Z.0090.B09.0706270921
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: Mac-F4228EC8
dmi.board.vendor: Apple Computer, Inc.
dmi.board.version: DVT
dmi.chassis.asset.tag: Asset Tag
dmi.chassis.type: 13
dmi.chassis.vendor: Apple Computer, Inc.
dmi.chassis.version: Mac-F4228EC8
dmi.modalias: dmi:bvnAppleComputer,Inc.:bvrIM51.88Z.0090.B09.0706270921:bd06/27/07:svnAppleComputer,Inc.:pniMac5,1:pvr1.0:rvnAppleComputer,Inc.:rnMac-F4228EC8:rvrDVT:cvnAppleComputer,Inc.:ct13:cvrMac-F4228EC8:
dmi.product.name: iMac5,1
dmi.product.version: 1.0
dmi.sys.vendor: Apple Computer, Inc.
system: architecture:       x86_64kernel:             2.6.31-6-generic

[lspci]
01:00.0 VGA compatible controller [0300]: ATI Technologies Inc M56P [Radeon Mobility X1600] [1002:71c5]
    	Subsystem: Apple Computer Inc. Device [106b:0080]