I obtained the recent developer-beta of Leopard given out at the recent WWDC and just installed it on my week old Santa-Rosa MBP. Aside from the great new features, I noticed several issues such as the fact that my MBP ran unusually hot compared to when it ran Tiger. I also had issues with some graphics, such as the strange pixilation sometimes. Finally, I noticed a greater hesitance to awake the notebook from sleep. I decided last night to revert back to Tiger, to much success. The only problem now is when I attempt to open applications such as Photo Booth or even System Preferences, the application just bounces on the dock once and ceases to open without notification. So far I have obviously restarted and ran the disk utility, all to no avail. Any ideas on how to get my brand new machine back into prime shape, running tiger? Thank you all.