Playlist shows too many lists and none of these others work.

I start my iRiver H340 player and press the A-B button, which gives me a list of the current playlists. Apart from the playlists I have put on there, there are many others, at least one for every subfolder on the machine. None of these other playlists work. If you press the folder name, it starts to try and read it and then says something along the lines of, "Read Failed!" It returns you to the first screen and one of my lists will work. However, scrolling through all of these bad playlists is not only time consuming, it seems unnecessary. The first thing I did was to do a search for the phantom filenames on the drive. But I couldn't find them. Also, they do not show up in the default "Playlists" folder. Only my working playlists are there. Help! How do I delete the phantom lists?