WARNING: at /build/buildd/linux-2.6.38/net/sched/sch_generic.c:256 dev_watchdog+0x213/0x220()

I can reproduce this bug:
- Open Firefox (homepage = standard)
- Navigate to speedtest.net

ProblemType: KernelOops
DistroRelease: Ubuntu 11.04
Package: linux-image-2.6.38-8-generic 2.6.38-8.42
Regression: Yes
Reproducible: Yes
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.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: ALC269 Analog [ALC269 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
Architecture: i386
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: ALC269 Analog [ALC269 Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: sander 2204 F.... pulseaudio
CRDA: Error: [Errno 2] Bestand of map bestaat niet
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xf7db8000 irq 44'
   Mixer name : 'Realtek ALC269'
   Components : 'HDA:10ec0269,104383ce,00100004'
   Controls : 12
   Simple ctrls : 7
Date: Sun Apr 17 11:34:52 2011
Failure: oops
HibernationDevice: RESUME=UUID=d0ef30e0-54b8-4f6e-a757-1b477c16d811
InstallationMedia: Ubuntu-Netbook 10.10 "Maverick Meerkat" - Release i386 (20101007)
MachineType: ASUSTeK Computer INC. 1005HA
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-2.6.38-8-generic root=UUID=761a9a4b-2bcc-45ec-ad32-f38a11b25355 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
SourcePackage: linux
Title: 8051] ------------[ cut here ]------------
UpgradeStatus: Upgraded to natty on 2011-04-13 (3 days ago)
dmi.bios.date: 02/26/2010
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1401
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: 1005HA
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: x.xx
dmi.chassis.asset.tag: 0x00000000
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK Computer INC.
dmi.chassis.version: x.x
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1401:bd02/26/2010:svnASUSTeKComputerINC.:pn1005HA:pvrx.x:rvnASUSTeKComputerINC.:rn1005HA:rvrx.xx:cvnASUSTeKComputerINC.:ct10:cvrx.x:
dmi.product.name: 1005HA
dmi.product.version: x.x
dmi.sys.vendor: ASUSTeK Computer INC.