Confused by Tags

[GavinB]

The log file seems to be throwing up a few odd messages now. Here's an example:
Warning: Ignoring conflicting custom value for ALBUM tag 'Anthology' in file Throwing Muses/Anthology/14-Bright Yellow Gun-Throwing Muses-Anthology.flac
applied sort value is '1993 - Anthology'; conflicting sort value is '2011 - Anthology'

I'm confused by this. It only seems to be picking up one track from the album. The file does have the Album Sort tag of 2011 - Anthology. Has it applied this value to the whole album?
Does this mean I've got another album called Anthology somewhere in my collection with a different Album Sort value? (I can't remember!)

The other two I've investigated have been Greatest Hits (definitely mutlple version of that title) and Heartbreaker (could be more than one - need to check).