removing default keybindings crashes compiz

[Jonathan]

PROBLEM
I want to remove the default keybindings to "move to workspace". Default it is:
left: ctrl + alt + left-arrow
right: ctrl + alt + right-arrow
top: ctrl + alt + up-arrow
bottom: ctrl + alt + down-arrow

If the default keybindings are set to "Disabled" compiz, or the unity-plugin (i can't tell exactly) won't come up. Unity2D is still working.

STEPS TO REPRODUCE
- remove or rename `.gconf` folder from ~ to restore all default settings
- signout and signin
- open System Settings / Keyboard / Navigation
- Change value of "Move to workspace left" to "disabled"
- Change value of "Move to workspace right" to "disabled"
- Change value of "Move to workspace top" to "disabled"
- Change value of "Move to workspace down" to "disabled"
- signout and signin
-> Won't login...

VERSION
I had no problems with Ubuntu 11.10 and early 12.04. The bug occured first with the updates of wednesday

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: unity 5.8.0-0ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-21.34-generic 3.2.13
Uname: Linux 3.2.0-21-generic x86_64
NonfreeKernelModules: wl nvidia
ApportVersion: 2.0-0ubuntu2
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]
Date: Sat Mar 31 19:05:55 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Beta amd64 (20120328)
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)

[Daniel van Vugt (vanvugt)]

Reproduced the crash. It seems to be bug 808007, not actually fixed despite being marked as fixed.