I used to have separate USB sticks for different sets of music and it always worked perfectly in my C200. Always picked up from where it left off. I've now put everything on one 128Gb stick and set up playlists but it doesn't work consistently. Often when I return to the car it says 'no device found' and I have to unplug and replug the usb. Also it might start playing the playlist I was on then suddenly start another. Any suggestions ?