Try deleting the song in question from your track listings using the little x on the right of the track name.

Re-upload the track/s, making sure the file is of a type MP3 and the MP3's ID3 tags have been filled out correctly.

To update your MP3s ID3 tags open the song in itunes or similar application and right hand click the track and select properties.  From here you will be able to update the track name, artist information and other relevant details.