International phonetic alphabet via Gentium font (in Theme Wizard)

Thank you very much for having added the theme wizard. I can now use International phonetic alphabet symbols!

Great!

OK, this is strange… Phonetic alphabel characters refuse to display, even with Gentium, but just half of the time… For exemple, it was OK in Title 1 and in the Body, but not in Title 2, or it was OK just with Gentium italic… It can change in the same session. I don’t understand, but it’s worrying… will my charaters display at the time of my presentation?