Simplenews and uninterpreted variables in confirmation mail

Hello,

I have set up a newsletter with the module Simplenews. For a user who has an account, or if it is opted out a newsletter from my home, he will receive a confirmation mail in which the variable will be interpreted Simplenews:

Example :

We received a request to unsubscribe address toto@mail.net the newsletter on the site www.monsite.com www.monsite.com located at http://www.monsite.com /. To confirm the unsubscribe, please click the following link: http://www.monsite.com/newsletter/confirm/remove/a76 ...

As if against a visitor who does not have an account on my site is, or opted out of the newsletter, he will receive the following confirmation message:

Example:

We have received a subscription request for the address !Mailto newsletter appointed Newsletter www.monsite.com on the !site Site located adress http://www.monsite.com. To confirm this subscription, please click the following link: http://www.monsite.com/newsletter/confirm/add/68ch ...

Have you an idea of the problem?

Thank's you.