When starting MM with the Music filter active, the artist and album nodes do not function. They only display "Unknown".

After opening the manage filters window, then pressing OK (with no changes), then the tree's will refresh and display properly.
edit:
this seems to occur specifically with the 'status is accessible' property.
The default 'music' filter works fine upon restart (with no status is accessible), however the default 'available tracks' filter shows the problem with 'status is accessible' property.
