Further characterization information to help Mark:

- Name of playlist, its parent playlists, and the songs within it? For example, does that playlist have any special non-alpha/non-US/URL-unfriendly characters along that branch of the playlist tree?

- Length of the URL that is generated when you click on the link to that playlist?

- What is the URL exactly, character-for-character?

- List all songs in the playlist?

- Does the same error occur in a different browser other than FFv23?