I have been trying to tackle this problem too. Something I found out was that a soundtrack album I have that is WMA encoded, displays the tags properly. It shows title, artist, album artist ("Soundtrack"), and album (movie name). In the widget it displays title, artist, and album artist.
An mp3 file with the same properties (per mp3tag) doesn't display artist at all. Just album artist.
An mp3 file with the same properties (per mp3tag) doesn't display artist at all. Just album artist.