Comment 1 for bug 905760

UPDATE:
Log from gnome-shell:

patrick@linuxmint ~ $ gnome-shell --replace
Fensterverwalter-Warnung:Log level 8: shell_tray_manager_manage_stage: assertion `manager->priv->stage == NULL' failed
Fensterverwalter-Warnung:Log level 16: Unable to register authentication agent: GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: An authentication agent already exists for the given subject
Fensterverwalter-Warnung:Log level 16: Error registering polkit authentication agent: GDBus.Error:org.freedesktop.PolicyKit1.Error.Failed: An authentication agent already exists for the given subject (polkit-error-quark 0)
      JS LOG: GNOME Shell started at Sat Dec 17 2011 20:38:59 GMT+0100 (CET)

(gnome-shell:24621): St-WARNING **: percentage lengths not currently supported

(gnome-shell:24621): St-WARNING **: percentage lengths not currently supported
    JS ERROR: !!! Exception was: Error: Error invoking TelepathyGLib.prepare_finish: The name org.freedesktop.Telepathy.AccountManager was not provided by any .service files
    JS ERROR: !!! lineNumber = '0'
    JS ERROR: !!! fileName = '"gjs_throw"'
    JS ERROR: !!! stack = '"("Error invoking TelepathyGLib.prepare_finish: The name org.freedesktop.Telepathy.AccountManager was not provided by any .service files")@gjs_throw:0
([object _private_TelepathyGLib_AccountManager],[object _private_Gio_SimpleAsyncResult])@/usr/share/gnome-shell/js/ui/telepathyClient.js:371
"'
    JS ERROR: !!! message = '"Error invoking TelepathyGLib.prepare_finish: The name org.freedesktop.Telepathy.AccountManager was not provided by any .service files"'

(gnome-shell:24621): folks-WARNING **: Error preparing Backend 'telepathy': The name org.freedesktop.Telepathy.AccountManager was not provided by any .service files
Bus-Zugriffsfehler
gnome-shell-calendar-server[24633]: Got HUP on stdin - exiting