Originally Posted by rockinrog
I can't help other than say it is definitely supposed to connect to two compatible devices:
Your G4 is designed to receive wireless stereo music from A2DP sources and mobile phones that support the Bluetooth A2DP and AVRCP profiles (mostly 3rd generation devices).
The G4 connects to my Blackberry Tour, for phone calls and A2DP music from the MP3 (stereo). When a call comes in, it overrides the music. Most of the time the music returns after the call is complete. The intercom to another G4 works the same way. The Bluetooth connection is from only one device (the phone with integral MP3) other than the connection to another G4.
Getting the G4 volume correct can be a chore, as the MP3 volume can be set from the phone but the phone call volume requires the noise canceling to sense ambient noise for the sensitivity. Sync the phone first, after the engine is running to get the G4 volume set for phone use, and then start the MP3 and adjust the MP3 player volume from the phone volume control (otherwise the volume will not match when switching between the two).