thinkpad_acpi has wrong symbols, doesn't get loaded

Using the Ubuntu Kernel thinkpad_acpi doesn't get loaded:
[ 4.045089] thinkpad_acpi: disagrees about version of symbol snd_ctl_add
[ 4.046460] thinkpad_acpi: Unknown symbol snd_ctl_add
[ 4.048403] thinkpad_acpi: disagrees about version of symbol snd_ctl_new1
[ 4.049756] thinkpad_acpi: Unknown symbol snd_ctl_new1
[ 4.051659] thinkpad_acpi: disagrees about version of symbol snd_ctl_boolean_mono_info
[ 4.053095] thinkpad_acpi: Unknown symbol snd_ctl_boolean_mono_info

Booting a vanilla 2.6.32.11 w/ the same .config works though:
Apr 19 10:57:34 t4 kernel: [ 4.648524] thinkpad_acpi: ThinkPad ACPI Extras v0.24
Apr 19 10:57:34 t4 kernel: [ 4.648526] thinkpad_acpi: http://ibm-acpi.sf.net/
Apr 19 10:57:34 t4 kernel: [ 4.648528] thinkpad_acpi: ThinkPad BIOS 6HET27WW (1.12 ), EC 6HHT14WW-1.02
Apr 19 10:57:34 t4 kernel: [ 4.648530] thinkpad_acpi: Lenovo ThinkPad T400s, model 2808D4G
Apr 19 10:57:34 t4 kernel: [ 4.649506] thinkpad_acpi: radio switch found; radios are disabled
Apr 19 10:57:34 t4 kernel: [ 4.649602] thinkpad_acpi: This ThinkPad has standard ACPI backlight brightness control, supported by the ACPI video driver
Apr 19 10:57:34 t4 kernel: [ 4.649604] thinkpad_acpi: Disabling thinkpad-acpi brightness events by default...

WORKAROUND: Uninstall linux-backports-modules-alsa-*.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: linux-image-2.6.32-21-generic 2.6.32-21.32
Regression: Yes
Reproducible: Yes
ProcVersionSignature: Ubuntu 2.6.32-21.32-generic 2.6.32.11+drm33.2
Uname: Linux 2.6.32-21-generic x86_64
AlsaVersion:
 Advanced Linux Sound Architecture Driver Version 1.0.22.1.
 Compiled on Apr 14 2010 for kernel 2.6.32-21-generic (SMP).
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: HDA Generic [HDA Generic]
   Subdevices: 0/1
   Subdevice #0: subdevice #0
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: HDA Generic [HDA Generic]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: a8 2090 F.... pulseaudio
 /dev/snd/pcmC0D0p: a8 2090 F...m pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xf2620000 irq 31'
   Mixer name : 'Conexant ID 5069'
   Components : 'HDA:14f15069,17aa2132,00100300'
   Controls : 6
   Simple ctrls : 4
Date: Mon Apr 19 15:21:19 2010
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=d458d815-7051-43aa-abb8-a2ce33c46cb4
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Beta amd64 (20100406.1)
MachineType: LENOVO 2808D4G
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-21-generic root=UUID=947fcfd5-1d1c-4b6f-bef1-2bf0e3be714b ro debug ignore_loglevel no_console_suspend
ProcEnviron:
 LC_CTYPE=en_UK.UTF-8
 PATH=(custom, user)
 LANG=en_GB.UTF-8
 SHELL=/bin/zsh
RelatedPackageVersions: linux-firmware 1.34
RfKill:
 0: phy0: Wireless LAN
  Soft blocked: no
  Hard blocked: yes
SourcePackage: linux
dmi.bios.date: 11/27/2009
dmi.bios.vendor: LENOVO
dmi.bios.version: 6HET27WW (1.12 )
dmi.board.name: 2808D4G
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:bvr6HET27WW(1.12):bd11/27/2009:svnLENOVO:pn2808D4G:pvrThinkPadT400s:rvnLENOVO:rn2808D4G:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 2808D4G
dmi.product.version: ThinkPad T400s
dmi.sys.vendor: LENOVO