Here is some info:
SI B 84 25 05
Phone, Navigation Systems January 2006
This Service Information bulletin supersedes S.I. B84 25 05 dated December 2005.
(New) designates changes to this revision
Software error in the Telematics Control Unit (TCU).
E90, E91 (3 Series) with SA639 (BMW Assist™ with Bluetooth® Technology) and SA663 (Radio Professional) from 9/1/05 to 12/13/05 production or vehicles programmed with CIP 19.01.00 or 19.02.00 or 19.02.03.
Intermittently, after a vehicle assumes sleep mode the handset does not connect/bond to the vehicle.
Intermittently, after the initial pairing of an approved Bluetooth enabled handset to the vehicle the handset displays a message that it failed to connect.
For all vehicles, on a customer complaint basis only, refer to the following procedure:
Update the complete vehicle per SI B09 05 01 (Coding, Individualization, Programming) Procedure B using CIP 20.00.01 (Target Data Status E089-05-12-510) or higher.