Unable to delete a music "file" from my iPhone while syncing

I have a file that is appearing under my iPod cover flow area on my iPhone 4. It says it is a song from an album, but when it is touched and flips, it says "Unknown Unknown" on the reverse side. It will disappear if I remove everything from my music library in iTunes, but the second I add ANY album or song back to my iPhone, it reappears again. It does NOT appear under my music list anywhere in iTunes. How on earth can I delete this when I cannot find it anywhere?