Random? freezes of compiz when using screen edge to maximize a window with unity running.

[Andreas Grois]

Binary package hint: unity

When maximizing a window by dragging it to the top-border of the screen, compiz freezes randomly. To me this only happened, when a second window on the same desktop was reaching a different desktop across a screen edge, yet I can't say whether this is required to reproduce the freeze.
Without doing anything else but just maximizing/restoring a nautilus-window after a few times the desktop freezes. The attached information was gathered from the frozen compiz-process.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: unity 3.8.4-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-8.41-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
NonfreeKernelModules: nvidia
.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 270.30 Fri Feb 25 14:34:55 PST 2011
 GCC version: gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu1)
Architecture: amd64
CompizPlugins: [core,bailer,detection,composite,opengl,imgjpeg,decor,mousepoll,move,compiztoolbox,snap,regex,place,imgpng,vpswitch,grid,gnomecompat,resize,animation,wall,unitymtgrabhandles,session,expo,workarounds,ezoom,staticswitcher,fade,scale,unityshell]
Date: Fri Apr 8 12:57:03 2011
DistUpgraded: Log time: 2011-04-04 09:49:20.908952
DistroCodename: natty
DistroVariant: ubuntu
DkmsStatus:
 nvidia-current, 270.30, 2.6.35-28-generic, x86_64: installed
 nvidia-current, 270.30, 2.6.38-8-generic, x86_64: installed
 nvidia-current, 270.30, 2.6.38-7-generic, x86_64: installed
ExecutablePath: /usr/bin/compiz
GraphicsCard:
 nVidia Corporation G96 [GeForce 9400 GT] [10de:0641] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: ZOTAC International (MCO) Ltd. Device [19da:9046]
JockeyStatus: xorg:nvidia_current - NVIDIA accelerated graphics driver (Proprietary, Enabled, In use)
ProcEnviron:
 LANGUAGE=de_AT:en
 PATH=(custom, user)
 LANG=de_AT.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: root=UUID=9df7c65b-1734-4d19-b341-9fadcadc22a6 ro quiet splash
ProcVersionSignature_: Ubuntu 2.6.38-8.41-generic 2.6.38.2
ProcVersionSignature__: Ubuntu 2.6.38-8.41-generic 2.6.38.2
ProcVersionSignature___: Ubuntu 2.6.38-8.41-generic 2.6.38.2
Renderer: Unknown
SourcePackage: unity
UpgradeStatus: Upgraded to natty on 2011-04-04 (4 days ago)
dmi.bios.date: 02/06/2007
dmi.bios.vendor: Intel Corp.
dmi.bios.version: CO96510J.86A.5773.2007.0206.0046
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: DQ965GF
dmi.board.vendor: Intel Corporation
dmi.board.version: AAD41676-402
dmi.chassis.type: 3
dmi.modalias: dmi:bvnIntelCorp.:bvrCO96510J.86A.5773.2007.0206.0046:bd02/06/2007:svn:pn:pvr:rvnIntelCorporation:rnDQ965GF:rvrAAD41676-402:cvn:ct3:cvr:
version.compiz: compiz 1:0.9.4+bzr20110407-0ubuntu2
version.ia32-libs: ia32-libs 20090808ubuntu11
version.libdrm2: libdrm2 2.4.23-1ubuntu6
version.libgl1-mesa-dri: libgl1-mesa-dri 7.10.1-0ubuntu3
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 7.10.1-0ubuntu3
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 2:2.14.0-4ubuntu6
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110107+b795ca6e-0ubuntu6