WARNING: at /build/buildd/linux-2.6.38/drivers/gpu/drm/radeon/radeon_fence.c:248 radeon_fence_wait 0x2ea/0x350 [radeon]()

I first had a message telling me that I don't have the required hardware to run Unity 3D. I was brought to the Ubuntu classic gnome desktop without Compiz. Then I logged out, logged in and was brought to UNITY 3D without trouble. And I got this message.

ProblemType: KernelOops
DistroRelease: Ubuntu 11.04
Package: linux-image-2.6.38-8-generic 2.6.38-8.42
Regression: Yes
Reproducible: No
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Annotation: Your system might become unstable now and might need to be restarted.
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: monfort 1796 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'ICH6'/'Intel ICH6 with ALC250 at irq 17'
   Mixer name : 'Realtek ALC250 rev 2'
   Components : 'AC97a:414c4752'
   Controls : 33
   Simple ctrls : 21
Date: Sun Apr 17 09:36:19 2011
Failure: oops
Frequency: This has only happened once.
HibernationDevice: RESUME=UUID=fd9f1498-3826-4403-8d0b-a0e7ce66f9b6
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
MachineType: Acer Aspire 5500
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-8-generic root=UUID=7ea3d9bc-d596-479f-9267-30a4afb1b19d 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:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
Title: WARNING: at /build/buildd/linux-2.6.38/drivers/gpu/drm/radeon/radeon_fence.c:248 radeon_fence_wait+0x2ea/0x350 [radeon]()
UpgradeStatus: Upgraded to natty on 2011-04-16 (0 days ago)
dmi.bios.date: 10/11/2005
dmi.bios.vendor: Acer
dmi.bios.version: V2.10
dmi.board.name: Mimid
dmi.board.vendor: Acer
dmi.board.version: *
dmi.chassis.type: 10
dmi.chassis.vendor: Acer
dmi.chassis.version: *
dmi.modalias: dmi:bvnAcer:bvrV2.10:bd10/11/2005:svnAcer:pnAspire5500:pvr:rvnAcer:rnMimid:rvr*:cvnAcer:ct10:cvr*:
dmi.product.name: Aspire 5500
dmi.sys.vendor: Acer