https://bugs.freedesktop.org/show_bug.cgi?id=52140
Bug #: 52140 Summary: Launcher and switcher icons disappeared Classification: Unclassified Product: DRI Version: XOrg CVS Platform: Other OS/Version: All Status: NEW Severity: normal Priority: medium Component: DRM/Radeon AssignedTo: dri-devel@lists.freedesktop.org ReportedBy: marius.kjeldahl@gmail.com
People are piling on reporting it here:
http://askubuntu.com/questions/163546/icons-from-unity-launcher-and-app-swit...
I do not know exactly which package broke it, but it seems most if not all are on Radeon systems with kernel 3.5 which I guess is an indication that they got it pulled in through the xorg-edgers PPA (my speculation at least).