Yes I've been to all of the links and the same problem some work and others don't so you need to look at it or you will be losing business. In my line of work they are considered unprofessional on the web without being coupled with other options for customers? Pdfs are web designers "Lazy way out" they save the designers time not the customers . . .
PDFs are not the best because each platform is different and all computers are equipped with different versions of pdf readers. Therefore you limit your popularity and market if you make people go away to download the right one. Not everyone is going to do that research shows most people don't.
I have adobe acrobat 9 pro one of the latest and your links to your pdfs are buggy on your site. Anyway rest assured I won't mention it again.