Alt+middle click resize of VirtualBox VM window causes resize box to freeze

[Lem]

STEPS TO REPRODUCE

1. Start VirtualBox OSE (currently 4.1.18-dfsg-1ubuntu1.1 installed)
2. Start a virtual machine (Windows or Linux, doesn't matter)
3. Alt+middle click on virtual machine window to resize

OBSERVED BEHAVIOUR

* Resize focus is lost, leaving the orange resize box stuck above all windows (retains its size even in Expo, i.e. it's above the workspaces)
* All resize functionality is lost, including via left click on borders of *any* windows.
* Closing the virtual machine window causes the orange resize box to disappear, restores all resize functionality, including window borders and alt+middle click.

EXPECTED BEHAVIOUR

* Orange box should resize as mouse is moved
* As middle mouse is released, virtual machine window should resize

I'm assuming this is a compiz issue, but something to do with VirtualBox and how it tried to grab input?

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: compiz 1:0.9.8.4+bzr3412-0ubuntu0.1
ProcVersionSignature: Ubuntu 3.5.0-19.30-generic 3.5.7
Uname: Linux 3.5.0-19-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 310.14 Tue Oct 9 11:52:41 PDT 2012
 GCC version: gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-2ubuntu1)
.tmp.unity.support.test.0:

ApportVersion: 2.6.1-0ubuntu6
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
Date: Sun Dec 2 21:17:07 2012
DistUpgraded: Fresh install
DistroCodename: quantal
DistroVariant: ubuntu
DkmsStatus:
 nvidia-experimental-310, 310.14, 3.5.0-17-generic, x86_64: installed
 nvidia-experimental-310, 310.14, 3.5.0-18-generic, x86_64: installed
 nvidia-experimental-310, 310.14, 3.5.0-19-generic, x86_64: installed
 virtualbox, 4.1.18, 3.5.0-18-generic, x86_64: installed
 virtualbox, 4.1.18, 3.5.0-19-generic, x86_64: installed
GraphicsCard:
 NVIDIA Corporation GF114 [GeForce GTX 560 Ti] [10de:1200] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: Giga-byte Technology Device [1458:3515]
InstallationDate: Installed on 2012-10-19 (44 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5)
MachineType: Gigabyte Technology Co., Ltd. GA-990FXA-UD3
MarkForUpload: True
PackageArchitecture: all
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-19-generic root=UUID=b1dc662d-1e66-426b-8c01-07a1f4cdb26b ro quiet splash
SourcePackage: compiz
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/30/2012
dmi.bios.vendor: Award Software International, Inc.
dmi.bios.version: F9c
dmi.board.name: GA-990FXA-UD3
dmi.board.vendor: Gigabyte Technology Co., Ltd.
dmi.board.version: x.x
dmi.chassis.type: 3
dmi.chassis.vendor: Gigabyte Technology Co., Ltd.
dmi.modalias: dmi:bvnAwardSoftwareInternational,Inc.:bvrF9c:bd08/30/2012:svnGigabyteTechnologyCo.,Ltd.:pnGA-990FXA-UD3:pvr:rvnGigabyteTechnologyCo.,Ltd.:rnGA-990FXA-UD3:rvrx.x:cvnGigabyteTechnologyCo.,Ltd.:ct3:cvr:
dmi.product.name: GA-990FXA-UD3
dmi.sys.vendor: Gigabyte Technology Co., Ltd.
version.compiz: compiz 1:0.9.8.4+bzr3412-0ubuntu0.1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.39-0ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 9.0-0ubuntu1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 9.0-0ubuntu1
version.nvidia-graphics-drivers: nvidia-graphics-drivers N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.13.0-0ubuntu6.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.3-0ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.99.99~git20120913.8637f772-0ubuntu1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.20.9-0ubuntu2
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.2-0ubuntu3

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.