Ctrl+Alt+0 does not minimise windows

On an up to date installation of Quantal, System Settings > Keyboard > Shortcuts > Windows shows a default shortcut of Ctrl+Alt+0 for Minimise Windows. This does not work however, it seems to have no effect.

If the shortcut is disabled then put back to Ctrl+Alt+0 it then works.

This may possibly related to bug #1063681 (ctrl+alt+0 does not work on Gala Window Manager)

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: unity 6.8.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.5.0-17.28-generic 3.5.5
Uname: Linux 3.5.0-17-generic i686
ApportVersion: 2.6.1-0ubuntu6
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: Mon Oct 29 13:44:51 2012
InstallationDate: Installed on 2012-08-01 (88 days ago)
InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Alpha i386 (20120730.1)
MarkForUpload: True
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)