[pastafarian]

Maybe get your hands on some other BT device like a headset to see if it does the same thing? Right now, it seems you don't know if it's a phone issue or a bt device issue. I had similar problems with my old 6700 and any bt headset. No amount of software tweaks had any positive effect, the phone had to be replaced. It frustrated the heck out of me, so I can guess what you're going through. Good luck!