Title bar "streaks" visible when minimizing maximized windows

[nerdy_kid]

Binary package hint: unity

To reproduce:

Open a window (say, banshee). Drag the launcher icon down to the bottom of the dock (helps make the streaks more visible). Maximize the window, and then minimize it. Pieces of the title bar get left behind as the window slides into the taskbar.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: unity 3.8.6-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic i686
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 Kernel Module 270.30 Fri Feb 25 14:34:41 PST 2011
 GCC version: gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu1)
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,compiztoolbox,decor,gnomecompat,imgpng,obs,snap,resize,unitymtgrabhandles,regex,vpswitch,neg,grid,move,mousepoll,animation,dbus,place,expo,session,workarounds,wall,ezoom,staticswitcher,fade,scale,unityshell]
CompositorRunning: compiz
Date: Wed Apr 13 17:24:38 2011
DistUpgraded: Log time: 2011-03-28 18:47:56.117090
DistroCodename: natty
DistroVariant: ubuntu
EcryptfsInUse: Yes
GraphicsCard:
 nVidia Corporation G84 [GeForce 8600M GT] [10de:0407] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: Dell Device [1028:0228]
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha i386 (20110302)
InstallationMedia_: Ubuntu 11.04 "Natty Narwhal" - Alpha i386 (20110302)
InstallationMedia__: Ubuntu 11.04 "Natty Narwhal" - Alpha i386 (20110302)
JockeyStatus:
 kmod:wl - Broadcom STA wireless driver (Proprietary, Enabled, In use) [auto-install]
 xorg:nvidia_current - NVIDIA accelerated graphics driver (Proprietary, Enabled, In use)
MachineType: Dell Inc. Vostro 1500
ProcEnviron:
 LANGUAGE=en_US:en
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-8-generic root=UUID=71f37bb6-cd0d-4152-bccb-82e4092c72d8 ro quiet splash vt.handoff=7
ProcVersionSignature_: Ubuntu 2.6.38-8.42-generic 2.6.38.2
ProcVersionSignature__: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Renderer: Unknown
SourcePackage: unity
UpgradeStatus: Upgraded to natty on 2011-03-28 (15 days ago)
dmi.bios.date: 04/21/2008
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A06
dmi.board.name: 0WY040
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvrA06:bd04/21/2008:svnDellInc.:pnVostro1500:pvr:rvnDellInc.:rn0WY040:rvr:cvnDellInc.:ct8:cvr:
dmi.product.name: Vostro 1500
dmi.sys.vendor: Dell Inc.
version.compiz: compiz 1:0.9.4+bzr20110411-0ubuntu1
version.libdrm2: libdrm2 2.4.23-1ubuntu6
version.libgl1-mesa-dri: libgl1-mesa-dri 7.10.2-0ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 7.10.2-0ubuntu1
version.nvidia-graphics-drivers: nvidia-graphics-drivers N/A
version.xserver-xorg: xserver-xorg 1:7.6+4ubuntu3
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.0-0ubuntu4
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.14.0-4ubuntu7
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110107+b795ca6e-0ubuntu7