HELP : main panel lost !!!

Hi, here is my problem :I had a Trinity perfectly working on oneiric,This afternoon I decided it was time to upgrade the whole oneiric, including the KDE 4,and since then there is no more main panel bar, or whatever you call it :no more menus, except for the desktop's one, no more notifications, not state icons, etc., only the naked desktop with application icons on it and nothing else. Does someone know of a way for me to recover from this state ?Daniele