WARNING: at /build/buildd/linux-2.6.38/fs/buffer.c:1151 mark_buffer_dirty+0x87/0xa0()

Apport reported this.

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
NonfreeKernelModules: fglrx
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
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: STAC92xx Analog [STAC92xx Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: alex 1955 F.... pulseaudio
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xcc600000 irq 43'
   Mixer name : 'IDT 92HD81B1X5'
   Components : 'HDA:111d7605,103c1412,00100402'
   Controls : 14
   Simple ctrls : 9
Card1.Amixer.info:
 Card hw:1 'HDMI'/'HDA ATI HDMI at 0xcc510000 irq 44'
   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: Wed Apr 6 13:27:54 2011
Failure: oops
Frequency: This has only happened once.
HibernationDevice: RESUME=UUID=37c5d4fa-458f-4897-bcd0-8f0ac29293ef
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100429)
IwConfig:
 lo no wireless extensions.

 eth0 no wireless extensions.

 vboxnet0 no wireless extensions.
MachineType: Hewlett-Packard HP ProBook 4720s
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-8-generic root=UUID=6feb69b6-a4f7-4a49-a790-07e328b3b8c2 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 1.49
RfKill:
 0: hci0: Bluetooth
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
Title: WARNING: at /build/buildd/linux-2.6.38/fs/buffer.c:1151 mark_buffer_dirty+0x87/0xa0()
UpgradeStatus: Upgraded to natty on 2011-03-29 (8 days ago)
dmi.bios.date: 09/16/2010
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: 68AZZ Ver. F.0B
dmi.board.name: 1411
dmi.board.vendor: Hewlett-Packard
dmi.board.version: KBC Version 57.31
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnHewlett-Packard:bvr68AZZVer.F.0B:bd09/16/2010:svnHewlett-Packard:pnHPProBook4720s:pvr:rvnHewlett-Packard:rn1411:rvrKBCVersion57.31:cvnHewlett-Packard:ct10:cvr:
dmi.product.name: HP ProBook 4720s
dmi.sys.vendor: Hewlett-Packard