All tags are populated correctly and appear correctly in the Album and Artist listings within Slimserver, but when you change the format of the "Now Playing" for the Squeezbox to include ARTIST it is just missing on the Squeezbox display.

To quote Than in the above thread -

"I think this has to do with the wma tags, which have fields for both Artist (Track Artist) and Album Artist. Standard tag editors and Windows Media Player only allow you to enter Artist. However a dedicated wma tag editor like Tag & Rename allow you to also make Album Artist entries.

If a wma file, which includes entries for both Album Artist and Artist is played on a Squeexe Box 2/3 with firmware 64 and Slim Server Server 6.5.0, Artist is lost on the screen. The problem is that these entries are presented as Album Artist and Track Artist (play a song and use right arrow key and scroll down through all fields to check this). However if Album Artist is left out in the wma-file, the Squeeze box presents it as Artist only and it will show up on the screen. It seems it is the Slim Server 6.5.0 that can't cope with Album Artist and Track Artist. I've tried to use a custom Title Format with both Album Artist and Track Artist with no success.

In previous firmware and Slim Server versions the Squeeze Box2/3 has always presented Track Artist as Artist even if the wma file has a Album Artist entry. This is the reason why it had worked before."