Only show main artist?

Basically, I want my music organized like this:

D:\Backup\Music\MP3\Artist[year] Album\00. Filename.mp3

And... I got that to work perfectly. It was very simple to do, it reorganized all my folders and everything to be proper. The problem is stuff like this:

D:\Backup\Music\MP3\Christina Aguilera[2006] Back to Basics Disc 1
D:\Backup\Music\MP3\Christina AguileraSteve Winwood[2006] Back to Basics Disc 1

Song 02 of Back to Basics Disc 1 is put into it's own directory because there is another artist. I do not want this. Is there a way to force a song to be with the rest of it's album no matter what, and only split up entire collaboration albums on their own? I'd rather not have to go through and manually change all of these, as I have a lot of CDs that have guest people or whatever on them, and so songs are getting mixed up in different folders when I just want them organized by the releasing artist.

Thanks!

EDIT: I have partially fixed this after searching google. I have used %band% instead of %artist%, but apparently I have some files that do not contain anything in the band field of the mp3 tag, as they are just in the root directory, but mostly it's just one stray file out of the entire album, kinda weird.