Shutdown fails, freezes on "ubuntu" screen

Shutdown appears to progress OK until second dot changes on "ubuntu" screen. Click is heard from hard disk (presumably heads parking?) then system freezes and requires manual shutdown.

Unbuntu 10.10

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: linux-image-2.6.35-24-generic 2.6.35-24.42
Regression: Yes
Reproducible: Yes
ProcVersionSignature: Ubuntu 2.6.35-24.42-generic 2.6.35.8
Uname: Linux 2.6.35-24-generic i686
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
Architecture: i386
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: pwait 1249 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'CMI8738'/'C-Media CMI8738 (model 55) at 0xa000, irq 17'
   Mixer name : 'CMedia PCI'
   Components : ''
   Controls : 41
   Simple ctrls : 22
CurrentDmesg:
 [ 14.949564] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro,commit=0
 [ 18.064792] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro,commit=0
 [ 22.320053] eth0: no IPv6 routers present
 [ 1031.571106] [drm:subconnector_show] *ERROR* Unable to find subconnector property
 [ 1031.571387] [drm:select_subconnector_show] *ERROR* Unable to find select subconnector property
Date: Wed Dec 22 18:13:50 2010
HibernationDevice: RESUME=UUID=0bff615a-4ad3-43cb-b27a-c2c6d045e470
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
IwConfig:
 lo no wireless extensions.

 eth0 no wireless extensions.
Lsusb:
 Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 001 Device 002: ID 046d:c016 Logitech, Inc. Optical Wheel Mouse
 Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
MachineType: System Manufacturer System Name
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.35-24-generic root=UUID=479a722f-2b51-4a22-b69b-038abb673392 ro quiet splash
ProcEnviron:
 LANG=en_GB.utf8
 SHELL=/bin/bash
RelatedPackageVersions: linux-firmware 1.38
RfKill:

SourcePackage: linux
dmi.bios.date: 04/30/2003
dmi.bios.vendor: Award Software, Inc.
dmi.bios.version: ASUS A7S333 ACPI BIOS Revision 1006
dmi.board.name: A7S333
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: REV 1.xx
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 7
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAwardSoftware,Inc.:bvrASUSA7S333ACPIBIOSRevision1006:bd04/30/2003:svnSystemManufacturer:pnSystemName:pvrSystemVersion:rvnASUSTeKComputerINC.:rnA7S333:rvrREV1.xx:cvnChassisManufacture:ct7:cvrChassisVersion:
dmi.product.name: System Name
dmi.product.version: System Version
dmi.sys.vendor: System Manufacturer