It seems like there are some PDF issues in version 10. I posted about export margins not working and they told me it was a bug that will be fixed in an update that will be released in about a week now. Other people have had to do ini file edits to bypass failures to export. My boss has been having hard crashes on pdf export. The issue you're having may just be another one.
Hopefully this update patch will address more pdf issues than just the margin failure that they told me about.