I guess these PDF files have DRM on them and apparently there aren't any readers out there yet.
I don't know about everyone else, but I keep trying and trying to justify using the Playbook tablet for professional reasons, but I'll be damned if I can actually do anything productive with it. Don't get me wrong - the browser is great and the device is stable. But compared to the iSuck and Android tablets there just aren't enough apps. And I'm not talking about the cutesy/fartsey apps that do the same functions as web sites.
It's very frustrating!!!