shadow flickering when moving window in virtualbox

[Thibaut Brandscheid]

12.04 Unity 3D in VirtualBox (guest additions installed) – 2 virtual monitors
ppa: lenses-testing

To test 12.04 multi monitor support I set up an vm with two virtual monitors. Since I started testing 12.04 (two months ago) the shadows start flickering (panel & top bar) when moving a window.

See attached video: 'shadow_flickering.ogv'

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: compiz 1:0.9.7.0+bzr3035-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-18.29-generic 3.2.9
Uname: Linux 3.2.0-18-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 1.94.1-0ubuntu2
Architecture: amd64
CompizPlugins: [core,composite,opengl,decor,mousepoll,vpswitch,regex,animation,snap,expo,move,compiztoolbox,place,grid,imgpng,gnomecompat,wall,ezoom,workarounds,resize,fade,unitymtgrabhandles,scale,session,unityshell]
CompositorRunning: compiz
Date: Sat Mar 17 12:31:54 2012
DistUpgraded: Fresh install
DistroCodename: precise
DistroVariant: ubuntu
DkmsStatus:
 virtualbox-guest, 4.1.8, 3.2.0-17-generic, x86_64: installed
 virtualbox-guest, 4.1.8, 3.2.0-18-generic, x86_64: installed
GraphicsCard: InnoTek Systemberatung GmbH VirtualBox Graphics Adapter [80ee:beef] (prog-if 00 [VGA controller])
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120217)
Lsusb:
 Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 001 Device 002: ID 80ee:0021 VirtualBox USB Tablet
MachineType: innotek GmbH VirtualBox
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-18-generic root=UUID=7187cce2-18c1-4ca2-9269-efdbebadb12d ro quiet splash vt.handoff=7
Renderer: Software
SourcePackage: compiz
UpgradeStatus: No upgrade log present (probably fresh install)
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
version.compiz: compiz 1:0.9.7.0+bzr3035-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.30-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 8.0.1-0ubuntu4
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 8.0.1-0ubuntu4
version.xserver-xorg-core: xserver-xorg-core 2:1.11.4-0ubuntu6
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.0-0ubuntu1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20111219.aacbd629-0ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.17.0-1ubuntu4
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20111201+b5534a1-1build2

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.