That was my first thought, but I was afraid to ask it...Check mute button on iPad.
So nothing in MPiV, MPext and MP logs? Can you post them here after pressing a radio channel?
I'd already read the bit about latest pictures and disabled the setting.About pictures, are you running the sevice with a user with access to the picture shares? Have you tried to configure FS Pictures in MPExt.? Please disable latest pictures since that give issues for some people.
In norway on vacation so there will be short answers for some days...