This might work as a "work-around", but it is a long-shot.
Install one of the free PDF writers and try printing to it from PAF Companion. The Preview and Publish functions will still not work as such, but if you can "print" a PDF copy you will have similar functionality. I think the PDF writer will need to be selected as the default printer in advance.
Verify that the PDF writer of your choice works with other applications (such as PAF) before trying it with PAF Companion. (I have a 32-bit system, so PAF Companion is not a problem. I just love to be able to create PDFs from all of my software by using PrimoPDF. It seems to me it might help you.)