Thanks for the find. I started a thread concerning a similar issue with PDFs. This is what I found related to converting from a PDF.
Programs that allow you to manipulate and extract info from PDF:
File Juicer ($17,http://echoone.com/filejuicer/
PDFpen and PDFpenPro ($50-100, http://www.smileonmymac.com/index.html
Program that allows you to join multiple pdfs into single file with Table of Contents:
PDF Lab (free, http://www.iconus.ch/fabien/products/pleng/pleng.html
w/r to just getting the PDF into a PRS-505 calibre, for the most part, worked as well as any of these programs
Hope this helps.