HUD keyboard shortcut always reset after an update

It's really frustrating that every time the update manager runs and applies an update, my keyboard shortcut for showing the HUD (default: Alt L) is reset to the default and I always have to set it back to something else (which I never use, like Shift+Ctrl+Alt+F12). I do this, because I have a xbindkeys mapping of Alt + Left / Alt + Right mapped to my Logitech 10 button mouse's forward/back thumb buttons.

I haven't noticed any other shortcuts changing after an update.
I never use the HUD and I don't really find it useful.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: unity 6.12.0-0ubuntu0.2
ProcVersionSignature: Ubuntu 3.5.0-26.42-generic 3.5.7.6
Uname: Linux 3.5.0-26-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 2.6.1-0ubuntu10
Architecture: amd64
CompizPlugins: [core,composite,gtkloader,opengl,copytex,decor,mousepoll,imgjpeg,commands,resize,place,imgsvg,regex,session,grid,compiztoolbox,imgpng,move,gnomecompat,animation,snap,wall,expo,fade,workarounds,ezoom,scale,unityshell]
Date: Thu Mar 14 15:36:14 2013
InstallationDate: Installed on 2011-11-17 (482 days ago)
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
MarkForUpload: True
SourcePackage: unity
UpgradeStatus: Upgraded to quantal on 2013-01-05 (68 days ago)