My bike is one year old this month. Last summer I went to a Nolan full face helmet w/J&M headset. Loved it so much, I eventually bought two more full helmets for my wife and son. Now that we've all had time to ride, here's the deal.
Helmet one: Nolan w/factory J&M - Drivers helmet
Helmet two: HJC with POS HD headset
Helmet three: HJC w/ J&M installed by J&M dealer
With either passenger, the front can transmit to the back, but not back to front. The INT shows in highlight like it's getting a signal, but I can't hear anything. My wife thinks I did it on purpose.

With helmet #2, which is my sons, I still cant hear him transmit, but the INT icon goes off and on like he is trying to transmit, and the music is muted as well, but he is not pushing the button. When we unplug the rear, it stops doing it.
I've made sure that the rear INT is turned on and the volume is loud enough. Would a dealer have the ability to trouble shoot this without all the helmets? The thought of taking all three full face helmets $$$$$$ and leaving them at the dealer is not promising. We've also switched helmets around with the same results, so I'm convinced the problem is in the bike electronics. Anybody else have anyproblems similar with regards to the intercom system? Music and mode buttons seem to work fine for the rear, it's just that it doesn't transmit.