Trouble with adding songs to my playlist....HELP

I am have trouble adding new songs to one of my playlists.  I have added the songs to my music on on Fuze and have tried both clicking and dragging, or copy and paste.  Using both methods, the songs are added separately to my Playlist folder, and not on the playlist that I want them included in.  What am I doing wrong?

Are you using Windows Media Player for the playlists?  If not, what are you using to edit the playlist?