How do you create PDF files on a MAC?

How are you creating the pdf files? Simply doing a save-as and choosing pdf should work fine from Ai. What is not working? What happens or doesn't happen. More details on the problem will help.

ESP files can only be read by people with mind-reading capabilities. Eps files should be working, though.

You're not saving over a network, by some chance? That can cause problems with pdfs and maybe with the eps files, as well. Do you have these problems if saving to your local hard drive?