New version of SongKong, importantly this fixes the problem with the Discogs Image Archive, the number of songs found with coverart should now increase.
There are also nice improvements for MusicBrainz matching to improve accuracy, improvements to memory handling and some bugs fixes including fixing some regressions.
http://jthink.net/songkong/news_build1032.jsp
The Discogs Images Saga is explained at http://blog.jthink.net/2014/05/a-new-discogs-image-archive.html