Problem with amounts of reservation

Hi,
First of all THANK YOU for this great Plugin !!

But ..

I have problems with teh amount indicated at every reservation i include in an event. I allways get that sentence and can’t publish my event :
Les détails pour votre évènement sont incorrects, et ne peuvent être publiées, veuillez corriger les erreurs suivantes :

Veuillez entrer un prix valide, par ex. 10,50 (sans le symbole monétaire)
Un problème s’est produit lors de l’enregistrement du billet.

wich means :

The details for your event are incorrect, and cannot be published, please correct the following errors:

Please enter a valid price, e.g. 10.50 (without the currency sign)

There was a problem registering the ticket.

What ever is the amount 320,00 or 320 … it appears to be “320, 00”. I tried to change the style, but it did not change anything.

Thanks for helping. I’an using it in french.