If you have a playlist showing up as <Empty>, either the format of the playlist os unrecognized, or the path to the songs (files) is incorrect.
If this is a playlist you manually created and transferred to the player while the player was connected to your computer, the only way to remove it is re-connect to your computer and delete it.
If you give us some information about the palylist, the format, how you created it, etc. maybe we can help you with getting it to work. 
