Recently year shows in year//year fromat in Tag-Panel? Why?

The years saved in the tags used to show as e.g. "1994" in the year column of the filelist, as well as in the tag-panel for the selected file.
Lately my Mp3Tag shows it as e.g. "1994//1994" in the tag-panel, but in the filelist it's still "1994"..

I updated Mp3Tag some days ago and i'm not sure whether it was like that before..
Is it a bug or some kind of feature? I have no idea what the sense of the double year should be.. Different Id-tag Versions?

Also, my MediaMonkey finds hundreds of "unsynchronized Tags" which is also new.. In 99% it's the year which it says is not synchronized.
I fear it has something todo with this Mp3Tag year problem.

Any ideas?

That's because Mediamonkey writes two year frames to the file.,9

Thank you very much! That was the perfect solution!

Is there a way for mp3tag to automatically overwrite this into a normal 4 digit year? I tried using the following, but it didn't work:

This trick should work:

Action #1:
Action type: Format value
Field: YEAR
Formatstring: x%year%

Action #2:
Action type: Replace
Field: YEAR
Original: x
Replace with:

[ ] only as whole word

[ ] case-sensitive comparison

Thanks dano, but that didn't work. After doing some studying it appears the problem is the DATE tag. I set up an action to remove that and it solves it.