Is_Home

I’m trying to view this code:

<div class="recent_posts">
        <?php query_posts('showposts=18'); ?>
	<?php while (have_posts()) : the_post(); ?>
                <a href="<?php the_permalink(); ?>" title="<?php the_title(); ?>"><a href="<?php the_permalink() ?>" rel="bookmark" title="<?php the_title(); ?>"><img src="<?php echo get_settings('home'); ?>/wp-content/uploads/<?php $values = get_post_custom_values("thumb_image"); echo $values[0]; ?>" alt="<?php the_title(); ?>" /></a>
        <?php endwhile; ?>
        </div>

on the home page only. This code sits on my sidebar outside of the loop. I’ve enclosed it with is_home(), however it doesn’t show up on the front page at all.

I would like to use this in conjunction with is_single() however I would like to query 9 posts instead of 18. How do I get this to work?