undo undoes everything in the session

I use mp3tag to translate/romanize song titles/filenames while at the same time tagging them, so I have big lists of files open at any given time to do things. Sometimes multiple unique versions of files are being dealt with so it benefits me to have an entire directory tree with sub folders open to tag/rename the same file, it saves me from having to search a list of translated names and apply it to each file in each directory.

Is it just me or does this happen to anyone else?

I have a bit of a nitpick with the behavior of the undo function. While tagging or renaming a list of files, if I use undo, it will undo everything I've edited since forcing a save on all tags/files.

Shouldn't it save a tag and file name after you hit enter? Why does it undo everything I've done? It's a bit frustrating when I'm trying to save time by sorting by tags and renaming, but then make one tiny paste error and undoing everything I've done in a half hour of work.

Yes, I did observe this behaviour of the history buffer too and was also frustrated.