Custom playlist columns do not save

Custom playlist columns (from addons) do not stay removed if the user sets them that way. In particular, I have the LyricMaster (1.6.1.1) addon installed. It adds a "lyrics" column. I can remove it, but when I close and open Songbird, it comes back. The rest of Songbird's columns behave properly: if you remove them, they stay removed.

Always reproducible. I understand this could be a problem with LyricMaster, but it is likely a problem with how Songbird handles addons.