With multiple monitors, clicking top-left corner of the screen closes the wrong window

[Alexey Kotlyarov]

On two monitors, it is possible to have two windows - say A and B - maximized side-by-side, each on its own monitor. When window A is active, hovering the spot where B's close button would be doesn't show the close button, and furthermore, clicking it closes A.

How to reproduce:
1. Have dual monitors set up as "multi-display desktop" (in ATI tool terms; might vary with others).
2. Open and maximize two windows (say A and B), each on its own desktop/monitor.
3. Activate A by clicking it.
4. Move the mouse to where B's close button would be - the top left corner of B's monitor.
5. Click the close button spot.

Expected results:
After (4), B's window control buttons appear. After (5), B is closed.

Actual results:
B's window control buttons do not appear. After (5), A is closed instead of B.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: unity 4.24.0-0ubuntu2b1
ProcVersionSignature: Ubuntu 3.0.0-13.22-generic-pae 3.0.6
Uname: Linux 3.0.0-13-generic-pae i686
NonfreeKernelModules: fglrx
ApportVersion: 1.23-0ubuntu4
Architecture: i386
CompizPlugins: [core,bailer,detection,composite,opengl,decor,imgsvg,snap,gnomecompat,mousepoll,imgjpeg,wall,place,session,grid,compiztoolbox,resize,imgpng,unitymtgrabhandles,vpswitch,move,regex,text,obs,animation,fade,expo,workarounds,scale,unityshell]
Date: Wed Nov 9 11:17:35 2011
InstallationMedia: Ubuntu 10.04.2 LTS "Lucid Lynx" - Release i386 (20110211.1)
ProcEnviron:
 PATH=(custom, user)
 LANG=en_AU.UTF-8
 SHELL=/bin/bash
SourcePackage: unity
UpgradeStatus: Upgraded to oneiric on 2011-10-16 (23 days ago)