Iphone Bluetooth car integration

[docrates]

The phone:
- Stock v1.1.1 iphone
- Jailbroken and activated via iNdependence
- Unlocked via AnySIM 1.1


The Car:
- BMW 325 e90
- iDrive and bluetooth kit

The problem:
- I can pair the phone, transfer address book and place a call
- But when I leave the car and come back...the car sees the phone and transfers the contacts...but looses connection with the phone as soon as the first call is made or received
- After that a complete un-pairing and re-pairing on both the car and phone will make it work again....until I leave the car once more and return
- Also happens with several other cars, including Audis
- I've already tried disabling wi-fi (Which conflicts with some phone-car combinations) with no luck.

Anyone has any insight?