WARNING: at /build/buildd/linux-2.6.31/fs/notify/inotify/inotify_user.c:398 inotify_remove_from_idr+0x7e/0x90()

I got this while running a system upgrade and doing quite some other stuff (transmission, gajim, kaffeine were all running). I have no real clue what the immediate cause of this might be.

ProblemType: KernelOops
Annotation: Your system might become unstable now and might need to be restarted.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: M2496 [M Audio Audiophile 24/96], device 0: ICE1712 multi [ICE1712 multi]
   Subdevices: 0/1
   Subdevice #0: subdevice #0
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: florian 3767 F.... pulseaudio
 /dev/snd/pcmC0D0p: florian 3767 F...m pulseaudio
 /dev/snd/controlC2: florian 3767 F.... pulseaudio
CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found.
Card0.Amixer.info:
 Card hw:0 'M2496'/'M Audio Audiophile 24/96 at 0x9400, irq 16'
   Mixer name : 'ICE1712 - multitrack'
   Components : ''
   Controls : 50
   Simple ctrls : 29
Card1.Amixer.info:
 Card hw:1 'UART'/'MPU-401 UART at 0x330, irq 10'
   Mixer name : ''
   Components : ''
   Controls : 0
   Simple ctrls : 0
Card1.Amixer.values:

Card2.Amixer.info:
 Card hw:2 'U0x46d0x8ad'/'USB Device 0x46d:0x8ad at usb-0000:00:02.1-1, full speed'
   Mixer name : 'USB Mixer'
   Components : 'USB046d:08ad'
   Controls : 3
   Simple ctrls : 2
Date: Tue Sep 22 13:43:21 2009
DistroRelease: Ubuntu 9.10
Failure: oops
HibernationDevice: RESUME=UUID=1c9f549d-7e80-4890-862d-625112d3cef3
IwConfig:
 lo no wireless extensions.

 eth4 no wireless extensions.

 eth3 no wireless extensions.
NonfreeKernelModules: nvidia
Package: linux-image-2.6.31-10-generic 2.6.31-10.34
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-10-generic root=UUID=a4ac4710-7160-4bc6-91db-ce40cc008844 ro quiet splash
ProcVersionSignature: Ubuntu 2.6.31-10.34-generic
RelatedPackageVersions:
 linux-backports-modules-2.6.31-10-generic N/A
 linux-firmware 1.19
RfKill:

SourcePackage: linux
Tags: kernel-oops
Title: WARNING: at /build/buildd/linux-2.6.31/fs/notify/inotify/inotify_user.c:398 inotify_remove_from_idr+0x7e/0x90()
Uname: Linux 2.6.31-10-generic i686
WpaSupplicantLog:

dmi.bios.date: 10/17/2003
dmi.bios.vendor: Phoenix Technologies, LTD
dmi.bios.version: 6.00 PG
dmi.board.name: nVidia-nForce
dmi.chassis.type: 3
dmi.modalias: dmi:bvnPhoenixTechnologies,LTD:bvr6.00PG:bd10/17/2003:svn:pn:pvr:rvn:rnnVidia-nForce:rvr:cvn:ct3:cvr: