Ok, GE thinks it has the latest version of BT fw. Replace the files into the RemoteSW folder. I don't have a zumo 660, but i think its fw and interface is close to a nuvi 765 which i do have. Go the the map page, press the speed field and then hold the speedometer for ~6 seconds to get into a hidden menu. Press 'Next' until you reach the 'Bluetooth Status' page. Press 'Clear' to delete all previously paired devices. If the field 'Update BT' is not greyed out you may be able to force a reload of the current BT fw.