Expo on multiple monitors of different resolutions is partially missing

[Robert Dyer]

I attached an external monitor to my laptop. The configuration is to span the monitors (no mirror):

left monitor: 1680x1050
right monitor: 1920x1200

they are aligned so the top edges match

I spread the workspaces (Super+S) and the display seems wrong. All of the workspaces (for both monitors) appear on the left monitor, and about 80% of the workspaces appear on the right monitor. See attached image.

I expected either a split (50/50) or duplication (100% on both).

Note that when I changed the right monitor's resolution to 1680x1050, spreading now does a 50/50 split (as expected?). See second attached image.

Description: Ubuntu 12.04.1 LTS
Release: 12.04

unity:
  Installed: 5.14.0-0ubuntu1
  Candidate: 5.14.0-0ubuntu1
  Version table:
 *** 5.14.0-0ubuntu1 0
        500 http://us.archive.ubuntu.com/ubuntu/ precise-updates/main i386 Packages
        100 /var/lib/dpkg/status
     5.10.0-0ubuntu6 0
        500 http://us.archive.ubuntu.com/ubuntu/ precise/main i386 Packages

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: unity 5.14.0-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-29.46-generic-pae 3.2.24
Uname: Linux 3.2.0-29-generic-pae i686
.tmp.unity.support.test.0:

ApportVersion: 2.0.1-0ubuntu12
Architecture: i386
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 Aug 14 23:31:04 2012
DistUpgraded: Fresh install
DistroCodename: precise
DistroVariant: ubuntu
DkmsStatus:
 virtualbox, 4.1.12, 3.2.0-25-generic-pae, i686: installed
 virtualbox, 4.1.12, 3.2.0-26-generic-pae, i686: installed
 virtualbox, 4.1.12, 3.2.0-27-generic-pae, i686: installed
 virtualbox, 4.1.12, 3.2.0-29-generic-pae, i686: installed
GraphicsCard:
 Advanced Micro Devices [AMD] nee ATI M66GL [ATI Mobility FireGL V5250] [1002:71d4] (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:20a4]
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423)
Lsusb:
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
 Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
MachineType: LENOVO 8743CTO
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   no card
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.2.0-29-generic-pae root=UUID=1c974264-624c-4947-8bc7-3ceeeb3035bd ro quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/16/2008
dmi.bios.vendor: LENOVO
dmi.bios.version: 7IET34WW (1.15 )
dmi.board.name: 8743CTO
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:bvr7IET34WW(1.15):bd07/16/2008:svnLENOVO:pn8743CTO:pvrThinkPadT60p:rvnLENOVO:rn8743CTO:rvrNotAvailable:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.name: 8743CTO
dmi.product.version: ThinkPad T60p
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.7.8-0ubuntu1.4
version.libdrm2: libdrm2 2.4.32-1ubuntu1
version.libgl1-mesa-dri: libgl1-mesa-dri 8.0.3-0ubuntu0.1
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 8.0.3-0ubuntu0.1
version.xserver-xorg-core: xserver-xorg-core 2:1.11.4-0ubuntu10.7
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.7.0-0ubuntu1.2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:6.14.99~git20111219.aacbd629-0ubuntu2
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.17.0-1ubuntu4.1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:0.0.16+git20111201+b5534a1-1build2

[Robert Dyer (psybers)]

Note: the monitor configuration I describe is the 2nd one listed in the MonitorsUser.xml.txt attached.

[Robert Dyer (psybers)]

compiz:
  Installed: 1:0.9.7.8-0ubuntu1.4
  Candidate: 1:0.9.7.8-0ubuntu1.4
  Version table:
 *** 1:0.9.7.8-0ubuntu1.4 0
        500 http://us.archive.ubuntu.com/ubuntu/ precise-proposed/main i386 Packages
        100 /var/lib/dpkg/status
     1:0.9.7.8-0ubuntu1.2 0
        500 http://us.archive.ubuntu.com/ubuntu/ precise-updates/main i386 Packages
     1:0.9.7.6-0ubuntu1 0
        500 http://us.archive.ubuntu.com/ubuntu/ precise/main i386 Packages

[jhfhlkjlj (fdsuufijjejejejej-deactivatedaccount)]

You can actually see that even the second image is not correct - it's a general issue with multi-monitor expose, which has historically been pretty bad with compiz. There are a billion bugs throughout many years dealing with this issue... See bug 919223 for starters. I don't know whether to dupe or not so I'll leave it.

[Launchpad Janitor (janitor)]

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

[Sami Jaktholm (sjakthol)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 438580, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.