C70 Aux In
 

Hi, got a '08 C70 with the high performance radio. It has the aux in button and plug in the armrest - but I cant get it to work, the AUX screen comes up on the display. I have used different cables, different sources but still nothing through the speakers.
Only other thing I can recall that the vendor of the car said that he changed the head unit a little while ago...all the other functions work on the system - any ideas.

thanks