Thanks for your commitment to this important issue. Those links were certainly interesting.

After reading them all, I promptly cleared every known Mac OS X font cache and rebooted. As almost all users from the various links had reported some level of resolution with this same procedure, I was hopeful. Alas, it was not to be, and upon reboot Preview was still unwilling to render TheSans Mono Condensed properly.

Knowing absolutely nothing about PDF creation but unwilling to accept this subpar fate for an otherwise exceptional work, I downloaded Acrobat Professional 8 Trial from Adobe.

One short hour later it was installed and ten minutes after that, The Ruby Programming Language PDF was rendering perfectly in Preview on Mac OS X.

Great news and it was a simple fix. I just exported the PDF as a PostScript "Level 2" file, including "Embedded and Referenced fonts" and then simply regenerated the PDF from the exported PS with Acrobat Distiller.

Again, pardon my ignorance of the document creation process in general. Here's a link to the screenshot showing both your original and the regenerated version rendered side-by-side:

http://socialface.com/failure/image/82798

If we could get a little closer to what the problem is, it would certainly be easier to file a bug against Preview...

Your level of dedication truly is what separates O'Reilly from the competition, thanks again.