Navigation System Saab 9.3 sports sedan aero

[Mobers]

After loading the 2006 DVD system gives fault messages like 'no disc' and check disc' çommunication fault'etc
Loading the 2003 disc gives problem now too, which dissapear after some time. When a 2003 disc is working correctly after several starts and stops, I changed the 2033 for the 2006 disk and it worked, but after stopping the engine problems occur again.
Dealer has loaded the latest software, but no result.
Does anyone recognise this issue and hopefully has a solution?
Thanks.
Ton Mobers