No Sound device after upgrade to 2.6.31-18 Kernel on 13,3" Macbook Pro

[Paul Koerbitz]

There is no sound device on my macbook pro (13,3", version 5,5) when booting into the latest 2.6.31-18 kernel on Karmic 9.10 64bit. If I go to System -> Preferences -> Sound -> (Tab) Hardware
no device are listed.

This problem does not occur if I boot into the 2.6.31-17 kernel (after booting into -18 I have to select the right device again and use the right settings in the alsa mixer but other than that everything works fine).

Please let me know if I can provide any more info.

thank you
Paul

ProblemType: Bug
AplayDevices: **** List of PLAYBACK Hardware Devices ****
Architecture: amd64
ArecordDevices: **** List of CAPTURE Hardware Devices ****
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/by-path', '/dev/snd/controlC0', '/dev/snd/hwC0D0', '/dev/snd/seq', '/dev/snd/timer', '/dev/sequencer', '/dev/sequencer2'] failed with exit code 1:
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'NVidia'/'HDA NVidia at 0xd3480000 irq 23'
   Mixer name : 'Cirrus Logic CS4206'
   Components : 'HDA:10134206,106b4d00,00100301'
   Controls : 0
   Simple ctrls : 0
Card0.Amixer.values:

Date: Sat Jan 23 17:03:22 2010
DistroRelease: Ubuntu 9.10
HibernationDevice: RESUME=UUID=17b290cc-f3c8-423f-b646-962bd2169328
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
MachineType: Apple Inc. MacBookPro5,5
NonfreeKernelModules: nvidia wl
Package: linux-image-2.6.31-18-generic 2.6.31-18.55
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.31-18-generic root=UUID=f8236a15-f852-45f2-8994-ba4a9a0e5910 ro quiet splash usbcore.autosuspend=1
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.31-18.55-generic
RelatedPackageVersions:
 linux-backports-modules-2.6.31-18-generic N/A
 linux-firmware 1.26
RfKill:
 0: hci0: Bluetooth
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
Uname: Linux 2.6.31-18-generic x86_64
dmi.bios.date: 06/15/09
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBP55.88Z.00AC.B03.0906151708
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-F2268AC8
dmi.board.vendor: Apple Inc.
dmi.chassis.asset.tag: Asset Tag#
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-F2268AC8
dmi.modalias: dmi:bvnAppleInc.:bvrMBP55.88Z.00AC.B03.0906151708:bd06/15/09:svnAppleInc.:pnMacBookPro5,5:pvr1.0:rvnAppleInc.:rnMac-F2268AC8:rvr:cvnAppleInc.:ct10:cvrMac-F2268AC8:
dmi.product.name: MacBookPro5,5
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.