Fire fox and Mozilla work fine with PDF files if you have have adobe acrobat installed. Maybe you have and old version of Adobe. I use Firefox all the time for pdf. It even embeds in web pages.
Nope. I'm using Acrobat 6.0, and have been using 6.0 since the initial release of Windows XP.
If you use Adobe Reader for PDFs, you must have a little program called Speed Up.
It speeds up AR opening.
Info:
http://fileforum.betanews.com/detail/1069854583/1