Anyone else had difficulty with the media player? At first my USB stick played fine. It even played .wav files, which my previous car would not. But today it seems stuck, showing only one .m4a file and not playing it. I set it to search for Tracks. It seemed only to know about the one .m4a file. Then it did nothing for quite a while, as if seaching. After a long time the whole infotainment system re-booted on its own coming up on the color Alfa Romeo badge screen. It still won't play from the USB stick. Has anyone else had the media player misbehave? Do .m4a files hang it up?