Does the platon command return before the window is closed? ie. does your perl program continue? Or is it that the second platon process simply refuses to start whilst there's another one in existance?

My guess is that it's the former (which is quite antisocial of platon), and therefore the fix would be to fork platon off into a separate process. Your perl will then continue, and can close the stray window (by whatever method; hopefully Giant is correct ;-) or simply start a second (and third, fourth and fifth, etc.) subprocess going, until the user screams for mercy under all those windows...

--
Tommy
Too stupid to live.
Too stubborn to die.