I'm trying out a Plantronics Voyager 510 headset on AKU 3.5 and mostly like it (decent volume, nice comfort). However, yesterday in the middle of a conversation the headset dropped the connection and the conversation switched over to the phone. I couldn't find a way to re-initiate it back onto the headset untl I deleted and re-paired it with the phone again. In addition, several times I've turned on the headset, had it beep at me since it detected a bluetooth signal, but couldn't get it actually working on the phone until I went into the bluetooth connections and simply pressed the "set as Hands-free" option on the device again (even though it was already selected). This is about the only way I've ever seen of getting the connection to start working again, other than re-pairing. All of this is a pain. Are others having problems as well, or is this possibly limited to the Voyager 510?

Not sure if this is the problem with yours, but the 6700 has a BT timeout feature which will turn off the BT after a bit. There's a hack posted here somewhere for changing that "feature."