Minimized windows on Unity launcher do not show correctly when pressing 'Super+W'

[Leo]

Minimized windows on Unity launcher do not show correctly when pressing 'Super+W'.
All other windows not minimized to launcher display a miniature image of the window content. Minimized applications only display a white page miniature, therefore either taking useful space for nothing, or just not being able to display the content of the minimized windows.

How to reproduce:

Launch several aplications (firefox, thunderbird, writer, calc....).
Minimize some of them to the Unity launcher.
Press 'Super+w'
Minimized applications appear as white page miniatures whereas not minimized applications display correctly.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: unity 5.8.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-23.36-generic 3.2.14
Uname: Linux 3.2.0-23-generic x86_64
NonfreeKernelModules: nvidia wl
.proc.driver.nvidia.gpus.0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/gpus/0'
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 295.33 Sat Mar 17 14:55:45 PDT 2012
 GCC version: gcc version 4.6.3 (Ubuntu/Linaro 4.6.3-1ubuntu4)
.tmp.unity.support.test.0:

ApportVersion: 2.0.1-0ubuntu1
Architecture: amd64
CompizPlugins: [core,composite,opengl,compiztoolbox,decor,vpswitch,snap,mousepoll,resize,place,move,wall,grid,regex,imgpng,session,gnomecompat,animation,fade,unitymtgrabhandles,workarounds,scale,expo,ezoom,unityshell]
CompositorRunning: compiz
Date: Wed Apr 11 13:32:49 2012
DistUpgraded: Fresh install
DistroCodename: precise
DistroVariant: ubuntu
GraphicsCard:
 NVIDIA Corporation G86 [GeForce 8400M GS] [10de:0427] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: Dell Device [1028:022e]
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta amd64 (20120328)
JockeyStatus:
 kmod:wl - Broadcom STA wireless driver (Proprietary, Enabled, In use) [auto-install]
 xorg:nvidia_current - NVIDIA accelerated graphics driver (Proprietary, Disabled, Not in use)
 xorg:nvidia_current_updates - NVIDIA accelerated graphics driver (post-release updates) (Proprietary, Enabled, In use)
MachineType: Dell Inc. XPS M1530
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-23-generic root=UUID=d38c1c6e-2743-466b-bd12-28db51f16245 ro quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)
XorgConf:
 Section "Device"
  Identifier "Default Device"
  Option "NoLogo" "True"
 EndSection
dmi.bios.date: 11/19/2008
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A12
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA12:bd11/19/2008:svnDellInc.:pnXPSM1530:pvr:rvnDellInc.:rn:rvr:cvnDellInc.:ct8:cvr:
dmi.product.name: XPS M1530
dmi.sys.vendor: Dell Inc.
version.compiz: compiz 1:0.9.7.4-0ubuntu3
version.ia32-libs: ia32-libs 20090808ubuntu35
version.libdrm2: libdrm2 2.4.32-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 8.0.2-0ubuntu3
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 8.0.2-0ubuntu3
version.nvidia-graphics-drivers: nvidia-graphics-drivers N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.11.4-0ubuntu10
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

[Leo (leopoldo-pena)]

Also attached a screenshot.

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 977189, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.