BUG: unable to handle kernel NULL pointer dereference at 00000004

I was trying to reproduce:

Bug #960604

This time, the screen went black, I got a text screen with error messages, but before I could read it, X seemed to switch back to/redraw my normal screen.

Exact steps with more detail than in the previous report:

- Insert USB device (SanDisk Sansa Clip+) with 4GB internal with an additional 16GB SHDC card. (this automounts two devices, one for each storage space)
- Copy some music onto SHDC part.
- Click "safely remove" SHDC part through right-click menu of launcher.

ProblemType: KernelOops
DistroRelease: Ubuntu 12.04
Package: linux-image-3.2.0-19-generic-pae
Uname: Linux 3.2.0-19-generic-pae i686
Annotation: Your system might become unstable now and might need to be restarted.
Architecture: i386
Date: Wed Mar 21 09:42:44 2012
Failure: oops
SourcePackage: linux
---
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: AD198x Analog [AD198x Analog]
   Subdevices: 0/1
   Subdevice #0: subdevice #0
ApportVersion: 1.94.1-0ubuntu2
Architecture: i386
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: AD198x Analog [AD198x Analog]
   Subdevices: 2/2
   Subdevice #0: subdevice #0
   Subdevice #1: subdevice #1
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: cas 2015 F.... pulseaudio
 /dev/snd/pcmC0D0p: cas 2015 F...m pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xfa220000 irq 46'
   Mixer name : 'Analog Devices AD1984A'
   Components : 'HDA:11d4194a,17aa20fb,00100200'
   Controls : 13
   Simple ctrls : 9
Card29.Amixer.info:
 Card hw:29 'ThinkPadEC'/'ThinkPad Console Audio Control at EC reg 0x30, fw 7THT15WW-1.00c'
   Mixer name : 'ThinkPad EC 7THT15WW-1.00c'
   Components : ''
   Controls : 1
   Simple ctrls : 1
Card29.Amixer.values:
 Simple mixer control 'Console',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [on]
DistroRelease: Ubuntu 12.04
HibernationDevice: RESUME=UUID=0c9beb45-6e79-4ff5-8f65-41a515fbfee9
MachineType: LENOVO 64771UG
Package: linux (not installed)
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.2.0-19-generic-pae root=/dev/mapper/hostname-root ro quiet splash pcie_aspm=force i915.i915_enable_rc6=1 vt.handoff=7
ProcVersionSignature: Ubuntu 3.2.0-19.30-generic-pae 3.2.11
RelatedPackageVersions:
 linux-restricted-modules-3.2.0-19-generic-pae N/A
 linux-backports-modules-3.2.0-19-generic-pae N/A
 linux-firmware 1.71
Tags: precise
Uname: Linux 3.2.0-19-generic-pae i686
UpgradeStatus: Upgraded to precise on 2012-03-21 (0 days ago)
UserGroups: adm admin cdrom dialout fax floppy lpadmin plugdev sambashare scanner syslog vboxusers
dmi.bios.date: 07/02/2008
dmi.bios.vendor: LENOVO
dmi.bios.version: 7TET33WW (1.07 )
dmi.board.name: 64771UG
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr7TET33WW(1.07):bd07/02/2008:svnLENOVO:pn64771UG:pvrThinkPadX300:rvnLENOVO:rn64771UG:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 64771UG
dmi.product.version: ThinkPad X300
dmi.sys.vendor: LENOVO