Do you have the Notification Area in your panel? It is not added by default. If not, alt+right click the panel (or alt+super+right click if using the compiz session), Add to Panel/Notification Area.
Do you have the Notification Area in your panel? It is not added by default. If not, alt+right click the panel (or alt+super+right click if using the compiz session), Add to Panel/Notification Area.