French words with quotation mark can't be searched

I'm using RH7 to create a project in French. When generating the WebHelp I enable the "TOC", "Index" and "Search" tabs. Everything looks fine until I use the Search Function. I type a word with quotation mark, such as "l'émetteur" or "d'actions", in the search box. It returns no result although I know for sure they appear in my project in many places.

Please help!