Non-maximized windows which sit on the border of a workspace move when called

As suggested in Bug #755842, post 54, I'm reporting a new bug. Here is how it can be reproduced every timer for me:
If workspaces are arranged like
12
34
1. Open GCStar program on workspace 4, non-maximized, touching right edge.
2. Open Firefox on workspace 1
3. When on workspace 1, click ok GCStar in launcher

The result is that GCStar window is moved so that part of it goes on workspace 3 and clicking on its icon on Launcher does not switch either to workspace 3 nor 4, it stays on 1.

This happens with other programs too, but with this one every time.

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: fglrx
.tmp.unity.support.test.0:

ApportVersion: 2.6.1-0ubuntu9
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CompositorRunning: compiz
Date: Sun Dec 16 16:19:44 2012
DistUpgraded: Fresh install
DistroCodename: quantal
DistroVariant: ubuntu
DkmsStatus: fglrx-updates, 9.000, 3.5.0-19-generic, x86_64: installed
GraphicsCard:
 Advanced Micro Devices [AMD] nee ATI Tahiti PRO [Radeon HD 7950] [1002:679a] (prog-if 00 [VGA controller])
   Subsystem: ASUSTeK Computer Inc. Device [1043:0424]
InstallationDate: Installed on 2012-12-16 (0 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5)
MachineType: To Be Filled By O.E.M. To Be Filled By O.E.M.
MarkForUpload: True
PackageArchitecture: all
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-19-generic root=UUID=0664e193-fd21-43df-9889-8d05f5e2513c ro quiet splash vt.handoff=7
SourcePackage: compiz
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/08/2011
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P1.00
dmi.board.name: Z68 Extreme4 Gen3
dmi.board.vendor: ASRock
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP1.00:bd07/08/2011:svnToBeFilledByO.E.M.:pnToBeFilledByO.E.M.:pvrToBeFilledByO.E.M.:rvnASRock:rnZ68Extreme4Gen3:rvr:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.name: To Be Filled By O.E.M.
dmi.product.version: To Be Filled By O.E.M.
dmi.sys.vendor: To Be Filled By O.E.M.
version.compiz: compiz 1:0.9.8.4+bzr3412-0ubuntu0.1
version.fglrx-installer: fglrx-installer N/A
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.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