Screen corruption problem with some opengl apps and ati

With ati opensource driver, when i turn on desktop effects in kde, when some effects are played (ex : wobbly windows) I see screen corruption in the windows diplayed (but not in plasma-desktop background, that's strange). When i turn them off all my desktop is displyed good.
Moreover, when I run bzflag (even without desktop effects) , all the content in the foreground flashes.
I had the same bug with xorg-edgers repository for lucid as soon I try a kernel = 2.6.35 (I forgot if this was in 2.6.34, but in 2.6.32 it worked good)

My config : dell xps 1640 with an ATI Mobility Radeon HD 3670 (M86)

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: xorg 1:7.5+6ubuntu2
ProcVersionSignature: Ubuntu 2.6.35-11.16-generic 2.6.35-rc5
Uname: Linux 2.6.35-11-generic x86_64
Architecture: amd64
DRM.card0.DisplayPort.1:
 status: disconnected
 enabled: disabled
 dpms: On
 modes:
 edid-base64:
DRM.card0.HDMI_Type_A.1:
 status: disconnected
 enabled: disabled
 dpms: On
 modes:
 edid-base64:
DRM.card0.LVDS.1:
 status: connected
 enabled: enabled
 dpms: On
 modes: 1366x768 1280x720 1152x768 1024x768 800x600 848x480 720x480 640x480
 edid-base64: AP///////wBMo0FUAAAAAAASAQOQIxR4Cof1lFdPjCcnUFQAAAABAQEBAQEBAQEBAQEBAQEBgxtWeFAAFjAwICUAYcYQAAAagxtWeFAAFjAwICUAYcYQAAAaAAAA/gBOMDgxRIAxNjBBVAogAAAAAAAAAAAAAAAAAAEBCiAgAAQ=
DRM.card0.VGA.1:
 status: disconnected
 enabled: disabled
 dpms: On
 modes:
 edid-base64:
Date: Tue Jul 27 19:23:43 2010
DkmsStatus:

GdmLog:
 Error: command ['kdesudo', '--', 'cat', '/var/log/gdm/:0.log'] failed with exit code 1: QInotifyFileSystemWatcherEngine::addPaths: inotify_add_watch failed: No such file or directory
 QFileSystemWatcher: failed to add paths: /home/mathieu/.config/ibus/bus
 Bus::open: Can not get ibus-daemon's address.
 IBusInputContext::createInputContext: no connection to ibus-daemon
 cat: /var/log/gdm/:0.log: No such file or directory
GdmLog1: Error: command ['kdesudo', '--', 'cat', '/var/log/gdm/:0.log.1'] failed with exit code 1: cat: /var/log/gdm/:0.log.1: No such file or directory
GdmLog2: Error: command ['kdesudo', '--', 'cat', '/var/log/gdm/:0.log.2'] failed with exit code 1: cat: /var/log/gdm/:0.log.2: No such file or directory
InstallationMedia: Kubuntu 10.10 "Maverick Meerkat" - Alpha amd64 (20100725)
MachineType: Dell Inc. Studio XPS 1640
ProcCmdLine: BOOT_IMAGE=/vmlinuz-2.6.35-11-generic root=/dev/sda7 ro quiet splash
ProcEnviron:
 LANGUAGE=
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
SourcePackage: xorg
Symptom: display
dmi.bios.date: 03/29/2010
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A14
dmi.board.name: 0U785D
dmi.board.vendor: Dell Inc.
dmi.board.version: A14
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: A14
dmi.modalias: dmi:bvnDellInc.:bvrA14:bd03/29/2010:svnDellInc.:pnStudioXPS1640:pvrA143:rvnDellInc.:rn0U785D:rvrA14:cvnDellInc.:ct8:cvrA14:
dmi.product.name: Studio XPS 1640
dmi.product.version: A143
dmi.sys.vendor: Dell Inc.
glxinfo: Error: [Errno 2] Aucun fichier ou dossier de ce type
system:
 distro: Ubuntu
 codename: maverick
 architecture: x86_64
 kernel: 2.6.35-11-generic