XnView Software

I really don't know how this works, but sometimes if I have checked files, move to another folder, come back, a couple of files are still checked.

Now the wierd thing is sometimes if I CLOSE xnview, reopen, then I would still have a checked file appearing in thumbnail mode.

It's random, not easily repeatable. Anyone have the same?

There is a tag category in tree pane, but I think it requires files to be placed there using only thumbnails view as the starting point.
This setting is for clearing list:
Options... View>Thumbnails>{Icon info}>Tagged file list must be cleared [____]^