Anybody ever seen this weirdness?

I've got a good looking PDF created using Prince that contains some OpenType fonts. You can download it from the server, it opens up in OSX Preview, and everything looks great. You can save it to your local hard drive, and everything still looks great. When you use File | Duplicate to make a local copy of the PDF, all the text using the OpenType font disappears. ?!?!?!?!

Does it maybe have something to do with the local computer not having that font, so that Duplicating/creating a new PDF doesn't can't use those fonts?

Does not happen if you use standard fonts like Arial.

Is the font an OpenType font with PostScript/CFF outlines, eg. a .otf file, not a .ttf file? Unfortunately, there are many long-standing bugs in MacOS X Preview affecting the use of OpenType fonts. We have a workaround for this in Prince 8.1, which avoids the problems in most cases.

Yes - they are .otf files. I figured it was an OSX Preview issue. Do you think if I purchased the .ttf versions of the fonts that it would likely work in Preview?

Yes, there should be no problems with .ttf fonts.