I have replaced my 20s to the 10u and my wife still has he 20s in her helmet.  After powering on both units and I press the - button on the 10u, instead of it saying 'intercom pairing' as the manual says it should, I hear 'group intercom' and the the 2 units do not pair (I followed the usual 'hold the jog' dial on the 20s until it says 'intercom pairing', however, I can't get them to pair up. 

Any help would be greatly appreciated.

Thank you.

Howard