Windows disappear when maximising by dragging onto panel

[Greg A]

Binary package hint: unity

1. Start with any unmaximised window
2. Click on it's titlebar to drag it around the screen (you can Alt+drag and get the same problem)
3. Drag the window to the top unity panel (so you mouse is over the panel)
4. The window dissappears until you release the mouse
(The window maximises as it should do)

You can get a similar effect dragging a maximised window using a the opposite method.

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
Architecture: amd64
CompizPlugins: [core,bailer,detection,composite,opengl,compiztoolbox,decor,resize,regex,vpswitch,move,animation,imgpng,mousepoll,grid,unitymtgrabhandles,gnomecompat,place,workarounds,wall,wobbly,expo,ezoom,staticswitcher,session,fade,scale,unityshell]
CompositorRunning: compiz
DRM.card0.HDMI.A.1:
 status: disconnected
 enabled: disabled
 dpms: Off
 modes:
 edid-base64:
DRM.card0.VGA.1:
 status: connected
 enabled: enabled
 dpms: On
 modes: 1280x1024 1280x1024 1152x864 1024x768 1024x768 800x600 800x600 640x480 640x480 720x400
 edid-base64: AP///////wAQrBRATFk4MiMQAQNoJh54Ls5Qo1RMmSYPUFSlSwBxT4GAAQEBAQEBAQEBAQEBMCoAmFEAKkAwcBMAeC0RAAAeAAAA/wA2NDE4MDY4UzI4WUwKAAAA/ABERUxMIDE5MDdGUAogAAAA/QA4TB9TDgAKICAgICAgACU=
Date: Sun Apr 10 17:35:39 2011
DistUpgraded: Log time: 2011-03-09 16:26:08.225547
DistroCodename: natty
DistroVariant: ubuntu
GraphicsCard:
 ATI Technologies Inc RV710 [Radeon HD 4350] [1002:954f] (prog-if 00 [VGA controller])
   Subsystem: Hightech Information System Ltd. Device [1787:2271]
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Alpha amd64 (20110127)
InstallationMedia_: Ubuntu 11.04 "Natty Narwhal" - Alpha amd64 (20110127)
InstallationMedia__: Ubuntu 11.04 "Natty Narwhal" - Alpha amd64 (20110127)
MachineType: Dell Inc. Dell DXP061
ProcEnviron:
 LANGUAGE=en_GB:en
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.38-8-generic root=UUID=8edb1aef-0dda-4612-8fdc-5373889f01d7 ro quiet splash vt.handoff=7
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 2011-04-06 (4 days ago)
dmi.bios.date: 11/22/2007
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 2.5.3
dmi.board.name: 0WG855
dmi.board.vendor: Dell Inc.
dmi.chassis.type: 7
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr2.5.3:bd11/22/2007:svnDellInc.:pnDellDXP061:pvr:rvnDellInc.:rn0WG855:rvr:cvnDellInc.:ct7:cvr:
dmi.product.name: Dell DXP061
dmi.sys.vendor: Dell Inc.
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.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