Thank you for your post and link to your blog.
Do you have other FileMaker Pro 9 files that also fail to print when converted to FileMaker Pro 12? If you create a new layout in the same converted file (do not duplicate the layout) with some conditional formatting and print, does the problem also occur? In essence, I'm trying to determine if this is a conversion issue, or if the original layout had some damage that manifested itself when converted to FileMaker Pro 12. Any additional information you can provide may be helpful.