I'll also confirm the same bug.
10.6 since the day it was released. I just purchased Pathfinder at a friend's house, and thought maybe the download was scruffy, came home and re-downloaded and had the same problem. It's on ALL the PDFs I'm seeing. The Corebook, Bonus Beastiary, Beastiary Preview, etc.
Apple is hammering out 10.6.1 right now and it's suppose to be out before the end of the weekend, hopefully this fixes the issue, cause I don't want to install Reader on my MBP...