Loaded Commerce Community

I have installed three languages - english (default language), dutch and french.
I installed the language packs and I added the languages in the admin page under 'Localization > Languages'.

In the Infobox Manager, I also activated the Languages.php, so customers can see three flags where they can change the language.

The problem is that this works fine, but when you click e.g. the french flag you do get a french page (with ...php?language=fr in the address), but when you click then another page, you return to an english page. When I type manually "?language=fr" in the address box behind the url, it's translated correctly.

What do I need to change so that you stay on french pages while surfing throughout the french webshop ?

strobo