Audio and USB problems

[kpo]

Sometimes when I start the car, the audio sticks on the Ford Audio screen, despite playing from the USB stick when being switched off. I usually can get it to work by pressing the AUX button, but even then it doesn't always work straight away.

I've also had some problems with "Error reading USB device" appearing - again not consistently but usually when changing from one playlist to another. Its not always the same playlist, and sometimes changing playlists works fine. If I keep trying to change the playlist, it usually works eventually.

I realise that if I ask my dealer to look at it, it will work perfectly. Anyone come across similar problems, or got any suggestions.