A client has an MICS system....they have 2 receptionists...both have Plantronics wireless headsets....one is working just fine....the other has problems....mic cuts out...doesn't seem to hold a charge and a clipping noise in her ear....have exchanged headsets between the two women....the problem stays with the same receptionist....have replaced parts and the problem remains....can it possibly be the phone?...this one has me stumped...any help for me?