I'm using the iPhone Bluetooth Headset with my Treo 680. One dilemma:

When I set the Treo settings to "Route all calls to headset," the iPhone headset auto-answers all incoming calls even when I don't want it to. (Solved it by turning off the "all calls to headset" Treo option in Prefs > Handsfree.)

But now I cannot route OUTGOING calls through the headset unless I try some random button combinations-- and then the call is only connected to the headset once the other end answers.

Any solutions? I imagine this is not limited to the iPhone BT set.