One of the things that makes the web interface clunky is a result of the use of 
frames.  After you add an album or a track to the playlist, a 'Back' usually 
causes the playlist to reload in its frame, rather than taking the user back in 
the browse frame.  If you add several individual songs, or if the playlist 
refreshes itself by its timer, then it usually takes several Backs to move the 
browse window up a level.

This can addressed by adding a Back link or button that exececutes a javascript 
history.back() to the pages within the browse frame.  This should make the page 
within the frame go back a level.  Put the link either be on the same line as 
the cookie crumb navigation (perhaps right-justified on the line) or 
immediately below it.