WARNING: at /build/buildd/linux-2.6.38/drivers/gpu/drm/radeon/radeon_fence.c:248 radeon_fence_wait 0x36f/0x3e0 [radeon]()

Screen freeze and flickers during 5 minutes, then it get back to life, with compiz crashed and a few other things.

ProblemType: KernelOops
DistroRelease: Ubuntu 11.04
Package: linux-image-2.6.38-8-generic 2.6.38-8.41
Regression: Yes
Reproducible: No
ProcVersionSignature: Ubuntu 2.6.38-8.41-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Annotation: Your system might become unstable now and might need to be restarted.
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: zxz 2435 F.... pulseaudio
CRDA: Error: [Errno 2] Aucun fichier ou dossier de ce type
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xfbff4000 irq 48'
   Mixer name : 'Realtek ALC889A'
   Components : 'HDA:10ec0885,1458a002,00100101'
   Controls : 38
   Simple ctrls : 21
Card1.Amixer.info:
 Card hw:1 'HDMI'/'HDA ATI HDMI at 0xfbbfc000 irq 49'
   Mixer name : 'ATI R6xx HDMI'
   Components : 'HDA:1002aa01,00aa0100,00100100'
   Controls : 4
   Simple ctrls : 1
Card1.Amixer.values:
 Simple mixer control 'IEC958',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [on]
Date: Mon Apr 11 14:38:17 2011
Failure: oops
Frequency: Once every few days.
MachineType: Gigabyte Technology Co., Ltd. EX58-UD5
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-8-generic root=UUID=94d6f07b-079b-4ec7-9387-a4fe6fdcc659 ro quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-2.6.38-8-generic N/A
 linux-backports-modules-2.6.38-8-generic N/A
 linux-firmware 1.50
RfKill:

SourcePackage: linux
Title: WARNING: at /build/buildd/linux-2.6.38/drivers/gpu/drm/radeon/radeon_fence.c:248 radeon_fence_wait+0x36f/0x3e0 [radeon]()
UpgradeStatus: Upgraded to natty on 2011-03-29 (12 days ago)
dmi.bios.date: 05/11/2009
dmi.bios.vendor: Award Software International, Inc.
dmi.bios.version: F7
dmi.board.name: EX58-UD5
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.modalias: dmi:bvnAwardSoftwareInternational,Inc.:bvrF7:bd05/11/2009:svnGigabyteTechnologyCo.,Ltd.:pnEX58-UD5:pvr:rvnGigabyteTechnologyCo.,Ltd.:rnEX58-UD5:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvr:
dmi.product.name: EX58-UD5
dmi.sys.vendor: Gigabyte Technology Co., Ltd.