Comment 2 for bug 1199877

This happens to me on a semi-regular basis too. Sometimes it's triggered by using menus, and sometimes by using indicators, but the symptoms are generally the same, unity-panel-service spins at 100%, menus and indicators lock up, and sometimes I'm unlucky enough to have them also steal focus, so I can't do anything else either until I kill unity-panel-service, or let it finish thinking about whatever has it in a tizzy (it will often recover after several minutes of spinning).