When using dual monitor some windows/dialogs do not open centered in the second screen

[Thiago Augusto Flessak]

I have 2 monitors, actually I have an external monitor connected to my laptop through hdmi.
The easiest way to reproduce the issue is following these steps:

1) When opening the "System Settings" in the first monitor (laptop), the window opens centered. That's the right behavior.
2) When opening the "System Settings" in the second monitor, the window appears in the left of the screen. I've attached a print screen.

This behavior occurs with others windows and dialogs too.

This only happens when using Unity 3D. I've tested on Unity 2D and everything works ok.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: compiz 1:0.9.7.8-0ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-24.39-generic-pae 3.2.16
Uname: Linux 3.2.0-24-generic-pae i686
ApportVersion: 2.0.1-0ubuntu7
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]
Date: Sun May 27 16:38:19 2012
DistroCodename: precise
DistroVariant: ubuntu
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423)
PackageArchitecture: all
SourcePackage: compiz
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

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