I c'ant transform my photoshop project as a .pdf file because my text has something wrong. I've narrowed down the problem as being the use of apostrophes or accents (when I'm working in French) in the texts.
It seems really unlikely that what you're encountering is an issue with the French accented characters. I just created a PDF document with every accented character, first in Bickham Script and then in Arial. Not the hint of a problem. I've also verified German, Russian, and Arabic as well.
Are you having this problem with every document you try or just a specific one? I'm wondering if that one particular file has become somehow corrupted.
What OS are you running? And which version of Photoshop?
Aussi, s'il est plus facile, nous pouvons continuer en français si vous voulez...