Multiple artist tag in FLAC files

[timster]

I just saw the post re. multiple artists in MP3 files but I have the opposite problem. I have a number of tracks with Artist tag set to artistsa/artistb. In the MP3 files I have, minimserver is able to split them so the track appears under both artists' index. However, for FLACs they just appear in the artist index as "artista/artistb".

Is this a limitation of Vorbis and/or is there a workaround? Or am I missing a step?