Had an upgrade fitted to take a newer Nokia (6310i) handset which needed a new MB phone unit. All fitted and works fine BUT.... now find the phone is too sensitive, IE during a conversation if the car noise is high, as with the top down, the volume drops so I cant hear the other person, if I turn up the volume it again works for a second or so, and again, the car noise overides the volume. So they hear me fine (very loudly) but I cant hear them. Anyone know how to fix this? May need a new microphone with the new unit?