This is a great clue.
I don't think it's genre either because there is a "Genre" tag in the MP3 files that it would pickup and not have to guess at. Also, most of my files have Genre populated and it's not showing up.
But clearly in your snapshot, uConnect is picking up something, so I think what I'm going to do is take a test song and put some values in each and every MP3 tag and see if one of the them show up.