so i just installed a new head unit, its a Dual XDM6400,(not the best brand, i know, but my friend was selling it brand new for $50) but i cant seem to get my mp3 player to work in the usb port. plugged it in and it just searches and searches and searches but never actually connects with it, i plugged in my clip drive and it played fine. i borrowed my friends ipod and plugged it in and it played music but wouldnt allow for operation or navigation of the ipod itself. for mine it was opposite, it would allow me to operate the mp3 player but no sound would play. its a creative zen micro by the way...6GB

any ideas?