[PTMonty]

Just a stab in the dark but are you sure the radio plays MP3s? I really don't know but the manual is usually pretty generic and covers all of the radio options. It could be your radio doesn't have MP3-ability. Are there any indications on the radio itself? A lot of radios have a little MP3 symbol. There should also be some MP3 specific functions/menu options if it does.

Just a thought.