I have a Zumo 550 and an Autocom Pro Avi with a bluetooth attachment. I paired them up for the first time and that's it. I get on the bike with my Nokia N73 in my pocket switch on the ignition and it all works......without touching a single button. takes about 10 - 15 seconds for it all to connect up. Zumo to Autocom first then Zumo to Nokia and off I ride. It's a superb setup!
Enjoy. Chris.