the trick is to define a dummy album artist (tag %band%) like "Various artists" or "Sampler Bravo Hits" or the like.
THe real artist then should be stored in the tag %artist%
So far the example looks alright - I take it that all "VA" bands are spelt the same ...
I do not know when you applied the "VA" band - sometimes WMP takes an awful time until it has reread alterations. If WMP thinks teh file has not been modified it will not update the database until it has played the track.
All alterations will only be considered if your NAS folder is one that WMP should watch - but you probably know that and have acted accordingly.
I feel quit ashamed, but the above tip did the trick
I thought I tested this already and W7 did not accept my nas as media folder. Perhaps this changed with the final W7, but I never tested it afterwards.