Man, I just spent way too long on this. Basically I discovered a security hole and closed it, but then spent three hours trying to allow the PDF generation utility to continue functioning normally. I've got it working again in a rather roundabout fashion; it's not perfect, but it does the trick. PDFs are now re-enabled for Dark Heresy.
Edity: I got mad at the sidebar at 6am and beat it up. Don't ask what it did; it knows what it did. Then Clarence made me do this:
It's like that all over the site now. Isn't CSS awesome? Also I will probably regret this tomorrow but right now it is fucking hilarious.