[KevinH]

Yes, the code to show the warnings was being entered twice before the first time finished (while the first was waiting at the ok button to be pressed it allowed other events to be processed which in turn made the MainWindow to be activated, triggering the second).

So it is a race / timing issue that may or may not happen all of the time or even at all on some systems. My fix just prevents the race / timing issue from causing a problem.