live-cd session can't shutdown or close the system

Hello,

I tested kubuntu ISO TESTING on VM virtualbox 3.1.6 on x86 64 and with live-cd session, i wasn't able to close my user session or shutdown the system

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 1.0.21.
AplayDevices:
 **** List of PLAYBACK Hardware Devices ****
 card 0: I82801AAICH [Intel 82801AA-ICH], device 0: Intel ICH [Intel 82801AA-ICH]
   Subdevices: 0/1
   Subdevice #0: subdevice #0
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: stars 1466 F.... knotify4
                      stars 1515 F.... kmix
 /dev/snd/pcmC0D0p: stars 1466 F...m knotify4
 /dev/snd/timer: stars 1466 f.... knotify4
CRDA: Error: [Errno 2] Aucun fichier ou dossier de ce type
Card0.Amixer.info:
 Card hw:0 'I82801AAICH'/'Intel 82801AA-ICH with STAC9700,83,84 at irq 21'
   Mixer name : 'SigmaTel STAC9700,83,84'
   Components : 'AC97a:83847600'
   Controls : 34
   Simple ctrls : 24
CurrentDmesg:
 [ 27.411182] eth0: no IPv6 routers present
 [ 35.215168] Intel AES-NI instructions are not detected.
 [ 35.355889] padlock: VIA PadLock not detected.
Date: Mon Apr 26 16:49:10 2010
EcryptfsInUse: Yes
HibernationDevice: RESUME=UUID=8488be99-e6e7-417e-86eb-f088e40b201a
InstallationMedia: Kubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100426)
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 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: innotek GmbH VirtualBox
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-21-generic root=UUID=50cdb9e7-1661-422e-9279-71f5e0c72271 ro quiet splash
ProcEnviron:
 LANGUAGE=
 LANG=fr_CH.UTF-8
 SHELL=/bin/bash
RelatedPackageVersions: linux-firmware 1.34
RfKill:

SourcePackage: linux
dmi.bios.date: 12/01/2006
dmi.bios.vendor: innotek GmbH
dmi.bios.version: VirtualBox
dmi.modalias: dmi:bvninnotekGmbH:bvrVirtualBox:bd12/01/2006:svninnotekGmbH:pnVirtualBox:pvr1.2:
dmi.product.name: VirtualBox
dmi.product.version: 1.2
dmi.sys.vendor: innotek GmbH