FrameMaker (v7.2 to 11): Custom font renders different when saving as PDF vs print PS and distill

Problem
I have a FrameMaker 10 document that uses a custom TTF symbols font. The symbols display fine in my FrameMaker document. When I Save As PDF, the symbols become squares in the PDF. If I choose the Adobe PDF printer in FrameMaker, make a .ps file and Distill it, the symbols come through fine. I am using Distiller X. Any idea why the output would be different using Save As versus .ps/Distill? Thanks in advance.
Solution
The problem appears to be associated with not using the RGB option when using the “save as PDF” option.
When you don’t use the RGB option, FrameMaker uses the old UNIX FrameMaker PostScript generator instead of using the Windows PostScript driver via GDI. Apparently that UNIX PostScript generator code had some problems mapping characters in Rick’s symbol font. It could have been a missing mapping table in the font itself.