No results

I used relevanssi before without problems. But new installation in a new theme i’m coding give me no results (using twentyeleven theme I have the same behaviour).
My search.php is really basic right now, to be sure there is no call for query_posts() or WP_Query():

<?php
	wp_head();
 ?>
	<h1>Search page</h1>
<ul>
<?php
if ( have_posts() ) : while ( have_posts() ) : the_post();

	$title=get_the_title();
	$excerpt = get_the_excerpt();
?>
	<li>
		<h3><a href="<?php the_permalink();?>"><?php echo $title;?></a></h3>
		<?php echo $excerpt;?>
	</li>
	<?php endwhile; ?>
</ul>
<?php else: ?>
<p>No results</p>
<?php endif;
wp_footer(); ?>

I obviously created the index. I just have two other plugin installed, WPML and MagicFields2, but deactivating them nothing change.
If I uninstall relevanssi I get the wordpress standard search results.
Any clue?

http://wordpress.org/extend/plugins/relevanssi/