I have a Plantronics 520 earpiece. Brand new Droid 4. First I had issues wiht Bluetooth phone audio flat out not working woth my SIP app, CSipSimple, i've simply accepted that it wont work, it had worked for standard phone calls though. Until it didnt anymore. My earpiece pairs, and when i place a call, the earpiece notifies me that it's conencted (it makes a tone letting me know that it's handling audio for the call) but it's realllly inconsistent. Sometimes i dont hear the Ringing (on outgoing calls), sometimes i'll hear the first ring, then silence until the other end picks up, sometimes i get no ringing, and I cant hear the person after they've picked up. On the heels of the really odd behavior i get out of CSipSimple, i'm leaning towards an issue with the phone, or Motorola's software rather than my Earpiece, which worked perfectly on my Droid Incredible. Anyone else having phone audio issues on their Droid 4?