XYplorer Beta Club

XY provides the internal properties (among others):

#mp3.album = MP3 Album
#mp3.artist = MP3 Artist
#mp3.Comments = MP3 Comments
#mp3.genre = MP3 Genre
#mp3.title = MP3 Title
#mp3.track = MP3 Track
#mp3.year = MP3 Year

I have a file: D:\Temp\Adele - Set Fire To The Rain.mp3

Tags set (via MP3Tag):
ARTIST Adele
GENRE Blue
TITLE Set Fire To The Rain
YEAR 2011

If I select it and execute I get an error message:

Property does not exist: mp3.year

Others like:
property("#mp3.title", "<curitem>");
property("#mp3.genre", "<curitem>");

work fine.

What's happening here?

ID3 tag type: v2.3 & v2.4 (tested with both)

It's even weirder.
I get that error msg, but then the year value does turn up (text property(...);) ( <-- to XYplorer)