Why are Firefox and Safari having problems with certain PDF files on the web? I'm having fits with a certain web PDF document using both Firefox and Safari.  Basically the document in question doesn't consist of one big pdf file; rather it consists of a bunch (20 or so) smaller files, one for each chapter or section, and the main page has file links to each of them.  In Firefox on a PC, clicking on the link for section 22 simply opens that PDF in the existing in-browser window.  In Safari or Firefox on Mac... it doesn't do anything - I can't navigate to or view section 22.  Similarly, downloading the individual files and saving them doesn't seem to work very well either, though I am thinking of downloading them and trying to re-create locally the directory/file structure the links seem to expect - still kind of a PITA.

Link to PDF document

Does anyone know of any browser add-on or other tool that could be used to view something like this on a Mac?
Adobe's Safari plugin for their PDF Reader doesn't work in 64 bit mode (and they don't supply a Firefox/Mac plugin at all!).

Try this Adobe kb article to see if setting 32-bit mode for Safari will work for you.  I had similar isses a while back, and I had to reinstall Reader (after upgrading to Snow Leopard) after doing this tip.