Yes, my assumption that it happens during the save process was indeed wrong. By pure chance I've seen this problem again within a file I've opened just for reading. So it happens even without typing just when scrolling through a file. The PSPad version I used when I saw it without saving or editing was 5.0.7 (701).
-- <https://forum.pspad.com/read.php?4,75123,76802> PSPad freeware editor https://www.pspad.com
