I recently updated my computer to a more powerful one, with a quad-core hyperthreading processor (i7), thus plenty of real concurrency available. Now I\'m occasionally>
System.exit() probably isn't the cleanest way of closing down a Swing based app
Can't you set your main frame to EXIT_ON_CLOSE:
mainFrame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE )
Then set it to invisible?
Related Q here; System.exit(0) in java