Just a guess but are you using the album artist (auto) field?. There is a flag in the config on that to set to Multiple Artists. Autotagging from the web though more often than not will just tag "Various Artist" that could explain why you have the two
I have always used Various Artists personally too .. I tag Album artist directly to the Album artist field during the rip or shortly there after not the album artist (auto field) -- you can do whatever you want or call a compilation zMisc. or what ever you want. But if you are consistant it will sort itself out. The Album Artist (auto field) will auto-populate the Album Artist field and vice versa. The (auto field) will fill itself out automatically if configured to do so. Your choice
If I have confused you read this
http://wiki.jriver.com/index.php/Album_Artist_and_Album_Artist_%28Auto%29What I would do is just select all the tracks in the whatever you do not want to use. And in the tag window, [Album Artist] field just choose the value you want to use ... if needed use the remove/rename/copy tool to consolidate the on your hard drive.