Flac labels are all in caps

I ripped a CD and created MP3 files and FLAC files. I used this wonderful mp3tag program to update the tags in both sets of files.

When I hover over the MP3 files and the info window comes up, it shows the tags, such as this:

Artist: Eagles
Title: In the City
Album: The Long Run
Track: 03
...and so on.

But when I hover over the FLAC files, it shows this:
ARTIST: Eagles
Title: In the City
ALBUM: The Long Run
TRACK: 03
...and so on.

So, most of the label names in the FLAC files are capitalized. I can't figure out why. This is a little thing, but it's driving me crazy lol.

Anybody have any ideas?

See e.g. here: