Recall on 500`s with rear drum brakes

Got a letter from the Norwegian import company with a recall notice that says that I have to call a Fiat garage as soon as possible. This only concerns 500`s with rear end drum brakes. It doesent say what the fault is exactly, but it has something to do with the rear brakes.... So I will have to give them a call tomorrow and make an appointment to get this thing fixed. Will try to get it together with an small service before the trip to Erba. My car has gone 13000 km`s today:'(