When copying files, sometimes there are files which already exist.
The great Total Commander is now asking to overwrite that file.
While he waits for an user-action, he background-checks that files against each other, and when he is sure that both files are identical, he skips that overwrite and closes the notification-window itself.
End of story
When the window closes itself, the keyboard and mouse inputs should be blocked for a couple of seconds - To avoid the user from pressing space etc. a few millisecs after the window closes and the new space-action would abort the whole process.
While background-checking a small progress-bar would be fine.
The checking should only be enabled when the size matches, and (via an option) only when the date matches, too.
In that case (date mismatch) he could skip the overwrite, but adjust the date only.