Media Centre Via Xbox360 Doesnt Read ID3 Tags Properly?

I am sure that there is an answer to this, but am lost... I have about 28,000 songs which are stored on my Windows 7 Enterprise Media Centre PC. All the ID3 tags are correct (I think), but I cant get the music library working properly on the PC or Extender.The problem I have is with my Various Artists albums... the ID3 tags show song title, artist and album artist. on a various artist album the Album Artist field is set to "Various Artists". I am using an Xbox360 media extended in my living room and whilst its slow, thats a seperate issue, there are some unexpected results when searching for songs...If you search for an artist, if they have produced albums where they are the only artist, then they are listed - the ID3 tags on their personal albums have the Album Artist field set as the Artist field and all works. However when listing by Artist, there is an artist listed called "Various Artists" and every song (12,000+) which is on a compilation album is listed as being by "Various Artists" as MC seems to get the artist name from the "Album Artist" field rather than from the "Artist" field.

I thought I'd found a workaround by changing the Album Artist field to be the same as the Artist - indeed this did work, but the unexpected side effect is that when you search by album, because each track on an album shows a different Album Artist set in the ID3 tag, it lists the album seperately for every song... so you may have "Now Thats What I Call Music xx" listed 20 times - once per song!Is there any way to get media centre to catalogue songs using the "Artist" field rather than the "Album Artist" field - but also to take into account that even though songs are by different artists, should the Album Artist all be the same - then to treat as a single album??I have only just started researching this and have read a bit about Media Centre using the catalogue created by WMP - but to be honest I have never used WMP and wouldnt know where to start.