Looks like it's finding the tags, but they're blank.
My guess is whatever tagging tool or ripper you're using is writing different information to the v1 and v2 tags. If you edit the artist info for a song using, say, Windows XP's Advanced Properties, delete the databases and re-index, does that song show up properly? If so, then making a pass with a different tagging tool may solve the problem.
Do you know what program created the tags on your songs? Can you E-mail one of the affected songs to me at celamantia@gmail.com for testing?
--Chris