I would check Software Update (in the Apple menu) to make sure you have the latest Java for Leopard , which was updated a few weeks ago. Of course, now that I say that, it's possible the update is what broke things for you, but I've used Citrix's GoToMyPC plenty since Apple upgraded Java for 10.6, and it uses a similar launcher.

I checked and the software is up to date, specifically Java. Now since I put 4 back on the machine, I get these random auditory ads preceded by a dog barking. Strange. Don't know if it's related. I'm afraid I'm not very computer savvy, so I do not know how to give more helpful information. I appreciate your help.