I've put music onto my MP3 and when I open the RCA file on 'My Computer' all of the music is in the folder. I can only find ten of my songs on the MP3 though. When I fast forward through the songs, the only songs on there are the original demo songs that came with the MP3 player and the ten songs that somehow made it onto the MP3, but I can't find the rest of the songs. What do I do to ensure that the other songs are on the MP3 player?