After an update of some software (Opera, VirtualBox and Pidgin) today, the Unity bar started to behave strange (since security and important updates are done in the background, I might have missed something). It started flickering but only when my mouse cursor was over it or when I clicked one of the launchers there to start an application. I read a couple of threads including a bug report on launchpad and most people claimed that it solved the problem by doing a unity --reset. The result was a Unity 3d bar duplicate (I'm using Unity 2d). I still haven't done a reset after this happened but I would like to know if this happened to anyone and if I should file a bug report. Here is a screenshot of how it looks like:
Note: I dragged the Unity 3d bar downwards in order for you to be able to see the Unity 2d bar underneath.