FastStone 7.6 Folder Renaming Mystery

I never had this problem with FastStone until I upgraded to version 7.6.

About 3/4 of the time, when I try to rename an existing folder by selecting it in the thumbnail view, I enter my new name in the little box and click Okay and instead get a warning refusal to rename the folder.

Once it starts this, it will not allow any folders to be renamed via the thumbnail view.

Curiously, when it disallows a renaming in thumbnail view, I can immediately rename that same folder in FastStone's tree view with no problem whatsoever.

This refusal to rename folders in thumbnail view may hang around through a couple sessions and then mysteriously start working again and just as mysteriously quit again with no rhyme nor reason for the behavior.

Whenever this happens, there is never any legitimate reason that the folder cannot be renamed; plus, if there was, then I shouldn't be allowed to rename it in tree view.

Has anyone else experienced this since upgrading to version 7.6 ?

No problem renaming a folder either way.
FSIV 7.6

No problem with FSIV 7.6 here either.

When I've had problems like this in the past with software in general, it's usually because something else is looking at the thing I'm trying to change. Another app with that folder visible, etc. Not a complete solution I know, but it may be worth making sure nothing else is open.