fonts won't convert

My adobe will not convert some fonts from powerpoint into pdf when I create the pdf document.

The fonts are present in the font library.  I can change the fonts once the pdf is created.  But this takes so much time.

Why won't they convert automatically when the file is created from the ppt?

And this only concerns some fonts... particularly Gotham.  Other fonts convert perfectly fine.

Thanks for helping - I am desperate.