By the way, in my situation this has happened with the User Switch Applet, with the Multiload Applet, and with the Window List applet. It's not deterministic and happens once in a while, about every fourth time upon session startup. This clearly doesn't seem to be applet-specific but rather more general purpose, related to the GNOME panel applet framework / architecture.
Sorry for stating marking the duplicates before - I've just noticed that it's automatically taken care by Launchpad.
I read https:/ /wiki.ubuntu. com/DebuggingGN OMEApplets but I don't have a clue how to debug this one because it clearly seems a race condition as others have suggested.
By the way, in my situation this has happened with the User Switch Applet, with the Multiload Applet, and with the Window List applet. It's not deterministic and happens once in a while, about every fourth time upon session startup. This clearly doesn't seem to be applet-specific but rather more general purpose, related to the GNOME panel applet framework / architecture.