Been using ubuntu since V5.04. Shortly after I installed 12.04 (I always install from scratch, never by the "upgrade" route), the little gizmo in the upper right corner that represents network connectivity stopped updating its visuals.
I have all the connectivity, I just don't get a proper visual representation of it; the applet or whatever it is just shows an empty pie-slice.
I've put up with that for the past 8 months or so. This morning I tried reinstalling Network-Manager. That didn't accomplish anything.