sat nav not working

[jay081181]

I have a 2002 Stilo Abarth but cant get the built in sav nave working. I have the disc for it but the cd player wont read it. the only way I can play music cd's is through the multichange, but the multi change wont read the map disc (it can be read on a laptop). think there must be a prob with the cd player on the stereo/satnav.........any ideas how I can overcome this problem????