BUG: unable to handle kernel NULL pointer dereference at 0000000000000038

Happens when I unplug the Huawei E220 USB modem

ProblemType: KernelOops
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: christian 2268 F.... knotify4
                      christian 2340 F.... kmix
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xefffc000 irq 21'
   Mixer name : 'SigmaTel STAC9200'
   Components : 'HDA:83847690,102801c2,00102201 HDA:14f12bfa,14f100c3,00090000'
   Controls : 13
   Simple ctrls : 8
Date: Tue Sep 29 09:13:34 2009
DistroRelease: Ubuntu 9.10
Failure: oops
HibernationDevice: RESUME=/dev/mapper/quincunx-swap_1
MachineType: Dell Inc. Latitude D620
NonfreeKernelModules: nvidia
Package: linux-image-2.6.31-11-generic 2.6.31-11.36
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcCmdLine: BOOT_IMAGE=/vmlinuz-2.6.31-11-generic root=/dev/mapper/hostname-root ro quiet splash
ProcVersionSignature: Ubuntu 2.6.31-11.36-generic
RelatedPackageVersions:
 linux-backports-modules-2.6.31-11-generic N/A
 linux-firmware 1.19
SourcePackage: linux
Tags: kernel-oops
Title: BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
Uname: Linux 2.6.31-11-generic x86_64
WpaSupplicantLog:

dmi.bios.date: 05/16/2008
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A10
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA10:bd05/16/2008:svnDellInc.:pnLatitudeD620:pvr:rvnDellInc.:rn:rvr:cvnDellInc.:ct8:cvr:
dmi.product.name: Latitude D620
dmi.sys.vendor: Dell Inc.