Many people have had problems with certain Photoshop products and Leopard. For me, Photoshop Elements 3 stopped launching as of 10.5.1. It would reach the end of its launch sequence, and die with a bus error. Over on the Apple Discussions forum, I found a solution that worked for me:
- Create a new Admin user.
- Log in as the new user.
- Install Photoshop Elements from your original disc.

