I'm not sure I understand why you're even bothering to convert HTML to PDF. Just save the HTMLs and view those. That's what I do with everything. I don't have to deal with any of the PDF problems discussed here (formatting, layout, zoom, missing objects, missing scrollbars, non-functional links). I had also ran into the problem of getting wierd memory errors on large/complex PDFs. Not to mention that the HTML takes up less space on the card.

I save HTML from just about everything I can. If it's more than just an individual page I want, then I use wget, or if I'm on the computer then I use one of the dozens of freely available programs for mirroring a site to my card.