Looks like you better get the pearl... Basic info off several BMW, BT forums.
The Blackjack does not have a "standard"
Microsoft (or other well supported) Bluetooth stack which is what causes these problems.
This is one of the current major problems of the phone (for us "tiny" number of Bluetooth users).
It's a huge oversight on
Samsung's part and we have no idea of if/when it will be fixed, which is a shame because the BJ is such a nice phone otherwise.
If you are a serious BT user then the BJ should probably be avoided until the BT probs get ironed out (if they do that is).