AlbumArtist Issues - creates more Albums

[Pastim]

I have now found out why, if I do not use an alias for AlbumArtist, I still get a slightly different album count from my other systems.

For example, I have an Album with one title, 9 tracks, in 3 folders. All have AlbumArtist defined as "Stern Isaac\\Zukerman Pinchas" (ie. 2 tag values).

6 have Artist as "Stern Isaac\\Zukerman Pinchas" (2 'works' in 2 different folders)
3 have Artist as "Stern Isaac\\Kilmer Richard" plus a conductor tag as "Zukerman Pinchas" (1 'work')

This produces two albums in the list, even though Album is the same of all tracks, and AlbumArtist is defined and is the same on all tracks.

If I change the Artist tags for the last 3 tracks to be Stern Isaac\\Zukerman Pinchas\\Kilmer Richard" I still get 2 albums.
If I change the Artist tags for the last 3 tracks to be Stern Isaac\\Zukerman Pinchas I get 1 album.

It looks as if the AlbumArtist is being ignored - is it because it is multi-valued?