Bluetooth connection Pioneer deh-p4900ib

I'm looking for help pairing my iPhone with my Pioneer bluetooth adapter for my car. I can pair, the problem is, every time I turn the ignition off I must reconnect (including password) once I've restarted the car. I have not experienced this with my prior phones so I believe it may be iPhone specific?

Any experience with this is appreciated.


Specs:

iPhone: 3.1.2
Receiver: deh-p4900ib
Bluetooth adapter: cd-btb200