Query to show older / newer blog posts

Hi,

we would like to split the blog into a page called “News” with alle blog posts youger than a year and a page called “Archive” containing all blog posts older than a year.

We use pre_get_posts filter, which will work fine on other templates, but not on enfold.

This is the code we use :

/**
 * Create date filter for posts older then current date
 */
function textdomain_date_range( $where = '' ) {
     $where .= " AND post_date < DATE_SUB(NOW(),INTERVAL 1 YEAR)";

    return $where;
}
/**
 * Displays the Post older then current date
 * @uses posts_where filer for data range
 * @uses pre_get_posts hook
 */
function textdomain_older_posts( $query ) {
    if ( is_page('Archiv') && $query->is_main_query() ) {
        $query->set( 'order', 'ASC' );
        add_filter( 'posts_where', 'textdomain_date_range' );
    }
    return $query;
}
add_action( 'pre_get_posts', 'textdomain_older_posts' );

The problem is, that no content ist displayed but we get a 404 Page. It is very strange, that when we alter the SQL query to somethin like that:

$where .= ” AND post_date < DATE_SUB(NOW(),INTERVAL 5 DAY)”;
it works perfectly. If I use a value higher than 5 DAY (eg. 7 DAY), i also get a 404. The SQL Query runs perfectly on the mysql server, and all values below 6 DAY work fine in wordpress.

Any help is appreciated to get this working.

Regards
Achim