[Plugin : Membership Lite] Posts are not displayed

Hi,

My english is not very well but I will try to explain you my problem.
I’m using Membership Version 2.0.7 on my website savoirsdexperience.com/ which is still in construction.
I have created two levels in membership :
– visitors : have only access to the following pages
* Accueil (Home page)
* Connexion (Sign up page)
* Actualités (News page which is supposed to display the posts)
– subscribers : have access to the entire content of the website.

The subscriber level works well, not the visitors one and I really don’t see why…
The positive rules for the Accueil and Actualités pages are ok (the pages are displayed), but when I click on Actualités in the menu, it doesn’t display the posts as it should but the no access page (page that explains to the visitor the content is restricted)…

I had the following error message :
‘Invalid argument supplied for foreach() wp-includes/query.php on line 2762’

that I fixed with the following hack :
‘// Always sanitize
if ( $this->post_count > 0 ) {
foreach ( $this->posts as $i => $post ) {
$this->posts[$i] = sanitize_post( $post, ‘raw’ );
}
}’

but it only remove the error message and doesn’t fix the problem of the posts not shown…

The first time I installed the Membership plugin, it worked very well. I had to reinstall all my blog due to the mistakes and now the Membership plugin doesn’t work well…

Any idea, suggestion, solution are very welcomed !
Thanks in advance for your time