2.6.32-20 does not boot on MacBook Pro 5.4

As per the subject. Works fine up to 2.6.32-19. After grub, I don't get the Ubuntu boot screen and the kernel falls back to console. Unfortunately, the failure text scrolls off the screen and I've failed to page up at this stage. grep found no reference to 2.6.32-20 in the relevant logs in /var/log either, so I am totally clueless about the error or what to try next. Please let me know what to try and I'll give more info.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: linux-image-2.6.32-20-generic 2.6.32-20.29
Regression: Yes
Reproducible: Yes
ProcVersionSignature: Ubuntu 2.6.32-19.28-generic 2.6.32.10+drm33.1
Uname: Linux 2.6.32-19-generic x86_64
NonfreeKernelModules: wl nvidia
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.21.
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: NVidia [HDA NVidia], device 0: Cirrus Analog [Cirrus Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: mario 1770 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'NVidia'/'HDA NVidia at 0xd3580000 irq 20'
   Mixer name : 'Cirrus Logic CS4206'
   Components : 'HDA:10134206,106b4c00,00100301'
   Controls : 16
   Simple ctrls : 9
Date: Mon Apr 12 21:52:27 2010
HibernationDevice: RESUME=UUID=92337538-1896-4589-b4a5-82716e6c01c3
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Alpha amd64 (20100131)
MachineType: Apple Inc. MacBookPro5,4
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-19-generic root=UUID=8d2a8ff1-ec5f-4fdb-8d1d-803044f16759 ro quiet splash
ProcEnviron:
 LANG=en_US.utf8
 SHELL=/bin/bash
RelatedPackageVersions: linux-firmware 1.33
RfKill:
 0: hci0: Bluetooth
  Soft blocked: no
  Hard blocked: no
SourcePackage: linux
dmi.bios.date: 06/15/09
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBP53.88Z.00AC.B03.0906151647
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-F22587A1
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookPro5,4
dmi.chassis.asset.tag: Asset Tag#
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-F22587A1
dmi.modalias: dmi:bvnAppleInc.:bvrMBP53.88Z.00AC.B03.0906151647:bd06/15/09:svnAppleInc.:pnMacBookPro5,4:pvr1.0:rvnAppleInc.:rnMac-F22587A1:rvrMacBookPro5,4:cvnAppleInc.:ct10:cvrMac-F22587A1:
dmi.product.name: MacBookPro5,4
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.