Frontend: show posts of the author

Hello.

I have the pro plugin.

I have unexpected results in frontend.

The author can only sort and view his posts. In wp-admin works fine, but in frontend the logged user (author) can see the posts of other authors.

I have this function that works fine, but in frontend does not.

add_action('pre_get_posts', 'query_set_only_author' );
function query_set_only_author( $wp_query ) {
 global $current_user;
 if( is_admin() && !current_user_can('edit_others_posts') ) {
    $wp_query->set( 'author', $current_user->ID );
    add_filter('views_edit-post', 'fix_post_counts');
    add_filter('views_upload', 'fix_media_counts');
 }
}

Can you help me?

Thanks in advanced