switcher doesn't show the preview a minimized window

[Ngassam Nkwenga]

It is about the new switcher Alt+Tab:
it doesn't show a preview of a minimized window.

way to reproduce it :
1- Open some window application.
2- minimizes one or many of the opened windows
3- use Alt+ Tab to navigate through the opened
4- see how the minimized windows have no preview.

What is espected :
1- Open some window application.
2- minimizes one or many of the opened windows
3- use Alt+ Tab to navigate through the opened
4- the minimized windows should have preview as well.

attached is screenshot of two minimized app: nautilus and Firefox. the focused app on the switcher is Firefox, but the area is just blank

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: unity 4.8.2-0ubuntu4
ProcVersionSignature: Ubuntu 3.0.0-9.12-generic 3.0.3
Uname: Linux 3.0.0-9-generic i686
NonfreeKernelModules: nvidia
.proc.driver.nvidia.agp.gpu:
 Fast Writes: Supported
 SBA: Supported
 AGP Rates: 8x 4x
 Registers: 0xff000e1b:0x1f004302
.proc.driver.nvidia.agp.host.bridge:
 Host Bridge: PCI device 8086:2570
 Fast Writes: Supported
 SBA: Supported
 AGP Rates: 8x 4x
 Registers: 0x1f004a1b:0x00000b02
.proc.driver.nvidia.agp.status:
 Status: Enabled
 Driver: AGPGART
 AGP Rate: 8x
 Fast Writes: Disabled
 SBA: Enabled
.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 Kernel Module 280.13 Wed Jul 27 16:55:43 PDT 2011
 GCC version: gcc version 4.6.1 (Ubuntu/Linaro 4.6.1-7ubuntu1)
Architecture: i386
BootLog:
 fsck from util-linux 2.19.1
 /dev/sda1: clean, 295402/655360 files, 2103063/2621440 blocks
CompizPlugins: [core,bailer,detection,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: Mon Aug 22 15:55:48 2011
DistUpgraded: Log time: 2011-06-27 10:49:22.000177
DistroCodename: oneiric
DistroVariant: ubuntu
DkmsStatus:
 nvidia-current-updates, 280.13, 3.0.0-8-generic, i686: installed
 nvidia-current-updates, 280.13, 3.0.0-9-generic, i686: installed
GraphicsCard:
 nVidia Corporation NV44A [GeForce 6200] [10de:0221] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: Device [196e:02f3]
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release i386 (20110427.1)
MachineType: Sony Corporation PCV-RSM22(CE)
ProcEnviron:
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.0.0-9-generic root=UUID=f81d0b0c-5911-46f4-99cb-6be48618e226 ro quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: Upgraded to oneiric on 2011-08-19 (2 days ago)
XorgConf:
 Section "Device"
  Identifier "Default Device"
  Option "NoLogo" "True"
 EndSection
dmi.bios.date: 06/26/2003
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1006
dmi.board.name: P4SD-VX
dmi.board.vendor: ASUSTek Computer Inc.
dmi.board.version: To be filled by O.E.M.
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: RS
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1006:bd06/26/2003:svnSonyCorporation:pnPCV-RSM22(CE):pvrToBeFilledByO.E.M.:rvnASUSTekComputerInc.:rnP4SD-VX:rvrTobefilledbyO.E.M.:cvnToBeFilledByO.E.M.:ct3:cvrRS:
dmi.product.name: PCV-RSM22(CE)
dmi.product.version: To Be Filled By O.E.M.
dmi.sys.vendor: Sony Corporation
version.compiz: compiz 1:0.9.5.0-0ubuntu5
version.libdrm2: libdrm2 2.4.26-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 7.11-0ubuntu3
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 7.11-0ubuntu3
version.nvidia-graphics-drivers: nvidia-graphics-drivers N/A
version.xserver-xorg: xserver-xorg 1:7.6+7ubuntu6
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.6.0-1ubuntu13
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20110811.g93fc084-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.15.901-1ubuntu2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110411+8378443-1