Subpages redirect me to the homepage ...

Hi!

This is my second problem. If i create pages, no problem, i can see them. But as soon as i create a subpage, if i try to go to that subpage, i'm redirected to the homepage of my website.

Example: http://projetsetudiants.fr/partenaires/proving-junior/
On the other hand, top level pages still works.

I can paste you my .htaccess:

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]

# uploaded files
RewriteRule ^files/(.+) wp-includes/ms-files.php?file=$1 [L]

RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule . index.php [L]

That's the default one i guess.

Thanks !