Restored maximized windows are "offset"

[Zordid]

Sometimes - not at all times - maximized windows that get either minimized to an icon or hidden by other windows don't get restored properly anymore when they come to the foreground again. There is a gap between the top menu unity bar and the window and ALL mouse clicks are interpreted at the wrong position - so it's a display bug as a mouse click reaches the "correct" element although it is not at the position it should be. See attached graphic which is LibreOffice but I also got that with Evolution or Firefox or any other window I often use in maximized mode.

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: unity 3.8.16-0ubuntu1~natty2
ProcVersionSignature: Ubuntu 2.6.38-11.49-generic 2.6.38.8
Uname: Linux 2.6.38-11-generic x86_64
NonfreeKernelModules: nvidia
.proc.driver.nvidia.gpus.0: Error: [Errno 21] Ist ein Verzeichnis: '/proc/driver/nvidia/gpus/0'
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 270.41.06 Mon Apr 18 14:53:56 PDT 2011
 GCC version: gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu4)
Architecture: amd64
CompizPlugins: [core,bailer,detection,composite,opengl,decor,mousepoll,vpswitch,regex,animation,snap,expo,move,compiztoolbox,place,grid,imgpng,gnomecompat,wall,ezoom,workarounds,staticswitcher,resize,fade,unitymtgrabhandles,scale,session,unityshell]
CompositorRunning: compiz
Date: Wed Sep 7 21:41:04 2011
DistUpgraded: Fresh install
DistroCodename: natty
DistroVariant: ubuntu
DkmsStatus:
 nvidia-current, 270.41.06, 2.6.38-11-generic, x86_64: installed
 nvidia-current, 270.41.06, 2.6.38-8-generic, x86_64: installed
 nvidia-current, 270.41.06, 2.6.38-10-generic, x86_64: installed
 vboxhost, 4.1.2, 2.6.38-11-generic, x86_64: installed
GraphicsCard:
 nVidia Corporation Device [10de:0dcd] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: Dell Device [1028:04b7]
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427)
InstallationMedia_: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427)
InstallationMedia__: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427)
JockeyStatus: xorg:nvidia_current - Beschleunigter Grafiktreiber von NVIDIA (Proprietär, Aktiviert, Nicht in Benutzung)
MachineType: Dell Inc. Dell System XPS L702X
ProcEnviron:
 LANGUAGE=de_DE:en
 PATH=(custom, user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-11-generic root=UUID=f89d4034-a3dd-495c-9ba4-babf3394c8a1 ro quiet splash vt.handoff=7
ProcVersionSignature_: Ubuntu 2.6.38-11.49-generic 2.6.38.8
ProcVersionSignature__: Ubuntu 2.6.38-11.49-generic 2.6.38.8
Renderer: Unknown
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/01/2011
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A11
dmi.board.asset.tag: Base Board Asset Tag
dmi.board.name: 03RG89
dmi.board.vendor: Dell Inc.
dmi.board.version: FAB1
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: 0.1
dmi.modalias: dmi:bvnDellInc.:bvrA11:bd06/01/2011:svnDellInc.:pnDellSystemXPSL702X:pvr:rvnDellInc.:rn03RG89:rvrFAB1:cvnDellInc.:ct8:cvr0.1:
dmi.product.name: Dell System XPS L702X
dmi.sys.vendor: Dell Inc.
version.compiz: compiz 1:0.9.4+bzr20110606-0ubuntu1~natty2
version.ia32-libs: ia32-libs 20090808ubuntu13
version.libdrm2: libdrm2 2.4.23-1ubuntu6
version.libgl1-mesa-dri: libgl1-mesa-dri 7.10.2-0ubuntu2.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 7.10.2-0ubuntu2.1
version.nvidia-graphics-drivers: nvidia-graphics-drivers N/A
version.xserver-xorg: xserver-xorg 1:7.6+4ubuntu3.1
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.0-0ubuntu4.1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.14.0-4ubuntu7.2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20110107+b795ca6e-0ubuntu7