This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
No no no no no. That was my first reaction when I saw your code. You are blocking the Event Dispatcher Thread with your sleep call, and that causes the entire user interface to block. Please read Concurrency in Swing.