infinite scroll doesn't work, maybe Im doing something wrong

ok Im trying to install the wordpress jetpack infinite scroll to my theme .
That’s the information here : http://jetpack.me/support/infinite-scroll/
(I have a custom theme )
So I added this piece of code to my function.php like they said

add_theme_support( 'infinite-scroll', array(
'type' => 'scroll',
'footer_widgets' => false,
'container' => 'content',
'wrapper' => true,
'render' => false,
'posts_per_page' => false,
) );

Doesn’t work my front-page doesn’t load posts after scroll
http://giantgag.com

Here’s my front-page.php
what Im doing wrong ??

<?php get_header(); ?>

	<div id="content">

		<?php
		while ( have_posts() ) : the_post();
		get_template_part( 'content', get_post_format() );
		?>

			<div class="index_thumb" >
				<a href="<? the_permalink()?>"><?php the_post_thumbnail( '250xXXX' ); ?>
					<div class="index_title"><?php the_title(); ?></div>
				</a>
			</div>

		<?php endwhile; ?>

	</div>
<?php wp_pagenavi();
wp_reset_query(); ?>

</body>
</html>

http://wordpress.org/plugins/jetpack/