Help Please Help

I have a Motorola Droid. I had downloaded Slacker and Pandora. Recently I have had a problem playing music files DL to my Droid. The Music player states that the song type is not supported on some songs. Neither Pandora nor Slacker will work. I am getting an Error code In Slacker: 1,-2147483648. Oddly enough YouTube videos will not play either. Does anyone know of a solution. Thanks.