Here is a link to the ArchiCAD wiki that deals with a somewhat similar issue to what you are experiencing. Try it first:
http://www.archicadwiki.com/Bugs/TextMissingInPDF?highlight=%28font%29|%28pdf%29|%2812%29
You can also perform your own search on the wiki in the upper right corner on the pages, but this was the closest I could find.
HTH