There are lots of issues with this thing. The dealer can actually do software updates which fixes lots of things such as this. I believe they would be free updates too, may even have a service bulletin for your specific problems.
It could also be a bad COMAND unit or other component in the sound system or a misconfigured fiber optic system.

Gilly

__________________
Click here to see the items I have up for auction at EBay

Click here to see a photo album of my '62 Sprite Project Moneypit (Now Sold)