Bluetooth connection

Hi
I hope some one can answer my question. I have a new Renault Laguna with a
carminat GPS / radio / phone connection. My mobile phone is Nokia 6233. The
phone makes contact through bluetooth within half a minute after starting
the car. But after 5 mintes the connection is gone. Switching the carminat
off and on helps; connection again for the following 5 minutes. In my former
car I never had any problem with the parot system.

According to my Renault garage the carminat is not compatible with my Nokia
6233. Only the following Nokia's are compatible: 6230i, 6020, N73 and N80.
For me a strange story I thought Bluetooth is Bluetooth and there are no
differences in the Bluetooth system.

What is wrong? Or is the garage right?
Regards
Peter