Mouse is still behaving with 'Sticky edges' on 2nd monitor with no launcher and stick edges turned off

I am working on my laptop with a second monitor attached (to the right of my laptop both virtually and physically).
I have the launcher only on the laptop, set to autohide.

When trying to get my cursor from the 2nd monitor onto the main/laptop screen (coming right to left) my cursor gets stuck on the left-hand edge of the 2nd monitor.
This happens if I move the cursor slowly and stays stuck there, it can't 'break through' onto the other monitor.
If I move the cursor quickly it doesn't get stuck and jumps to the other monitor fine.

I'm using a Logitech Tracman trackball-style mouse but just tried with a traditional optical mouse and the same behaviour is observed.

It appears to be fine after a fresh boot, but after a hibernate/wakeup cycle (i.e. close and open laptop lid) this sticky edge behaviour is observed.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: unity 6.6.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.5.0-15.22-generic 3.5.4
Uname: Linux 3.5.0-15-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.5.2-0ubuntu4
Architecture: amd64
CompizPlugins: [core,composite,opengl,compiztoolbox,decor,vpswitch,snap,mousepoll,resize,place,move,wall,grid,regex,imgpng,session,gnomecompat,animation,fade,unitymtgrabhandles,workarounds,scale,expo,ezoom,unityshell]
CompositorRunning: compiz
Date: Tue Sep 25 09:39:03 2012
DistUpgraded: 2012-09-11 14:32:56,350 DEBUG enabling apt cron job
DistroCodename: quantal
DistroVariant: ubuntu
DkmsStatus:
 virtualbox, 4.1.18, 3.2.0-30-generic, x86_64: installed
 virtualbox, 4.1.18, 3.5.0-14-generic, x86_64: installed
 virtualbox, 4.1.18, 3.5.0-15-generic, x86_64: installed
GraphicsCard:
 Intel Corporation Core Processor Integrated Graphics Controller [8086:0046] (rev 02) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:215a]
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
MachineType: LENOVO 2516CTO
ProcEnviron:
 LANGUAGE=en_NZ:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_NZ.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-15-generic root=UUID=c5da1e89-74fe-4142-8b82-330db6bba767 ro quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: Upgraded to quantal on 2012-09-11 (13 days ago)
dmi.bios.date: 06/07/2010
dmi.bios.vendor: LENOVO
dmi.bios.version: 6IET65WW (1.25 )
dmi.board.name: 2516CTO
dmi.board.vendor: LENOVO
dmi.board.version: Not Available
dmi.chassis.asset.tag: No Asset Information
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvr6IET65WW(1.25):bd06/07/2010:svnLENOVO:pn2516CTO:pvrThinkPadT410:rvnLENOVO:rn2516CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 2516CTO
dmi.product.version: ThinkPad T410
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.8.2+bzr3377-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.39-0ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 9.0~git20120917.7cfd42ce-0ubuntu3
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 9.0~git20120917.7cfd42ce-0ubuntu3
version.xserver-xorg-core: xserver-xorg-core 2:1.13.0-0ubuntu4
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.3-0ubuntu1
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 2:2.20.8-0ubuntu1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.2-0ubuntu1