I have an 8gb Sandisk USB stick formatted FAT32. I have been trying to copy the mp4a (unprotected apple lossless format - I ripped my own cd's, not purchased from Apple). When I put the USB stick into the car, the system recognizes the album artwork and song titles, but will not play the songs. I'm on FW 5.0, if that makes any difference. the only way I have been able to play from USB is to do a new flac rip of a cd. No album art, but the songs play. i just don't want to re rip all of my cds! any suggestions?