To resolve this issue:
- Open the project in any of QuarkXPress 7.x versions and Export it down to version 6.0.
- Open the down-saved project in QuarkXPress 6.5
- Go to File > Export layout as PDF. In the PDF Options dialog, in the Job Options tab, select Embed All fonts.
- Save the PDF
- Save the project in QuarkXPress 6.5
- Open the project in QuarkXPress 7 and export a PDF with the default setting.
Fonts will be embedded correctly in the PDF.