I am pretty surprised this was never confirmed -- I've read reports of it all over the internet (though it's possibly an upstream bug). It happens also on KDE, so it's not just a GNOME thing.
What fixes it is to turn off and on the tray icon a couple of times. Obnoxious fix, but it's not so terrible if you're going to be working for long periods in the same session.
I am pretty surprised this was never confirmed -- I've read reports of it all over the internet (though it's possibly an upstream bug). It happens also on KDE, so it's not just a GNOME thing.
What fixes it is to turn off and on the tray icon a couple of times. Obnoxious fix, but it's not so terrible if you're going to be working for long periods in the same session.