sort posts by custom field date

Hi All,

I hope someone can help. I’ve got the following code in my index.php file to sort the posts by date d/m/y then title.

<?php $posts = query_posts( $query_string . 'meta_key=Day&meta_key=Month&meta_key=Year&order=asc' ); ?>

<?php if( $posts ) : ?>

	<?php foreach( $posts as $post ) : setup_postdata( $post ); ?>

	<!-- listings_wrapper -->
	<div id="listings_wrapper">

	  <!-- listings_content -->
	  <div id="listings_content">
		<h1><a href="<?php the_permalink() ?>" rel="bookmark"><?php the_title(); ?></a></h1>
		<p><?php $key="Venue"; echo get_post_meta($post->ID, $key, true); ?></p>
		<p><span><?php $key="Date"; echo get_post_meta($post->ID, $key, true); ?></span></p>
		<p><a href="<?php the_permalink() ?>">more info</a></p>
	  </div>
	  <!-- /listings_wrapper_content -->

	  <!-- listings_thumbnail -->
	  <div id="listings_thumbnail">
	  <?php the_post_thumbnail( 'listings-post-thumbnail' ); ?>
	  </div>
	  <!-- /listings_wrapper_thumbnail -->

	</div>
	<!-- /listings_wrapper -->

	<?php endforeach; ?>

<?php else: ?>

	<p><?php _e('Sorry, no events matched your criteria.'); ?></p>

<?php endif; ?>

This works well. I’d also like this to work on my archive.php file to replace:

<?php if (have_posts()) : while (have_posts()) : the_post(); ?>

	<!-- listings_wrapper -->
	<div id="listings_wrapper">

	  <!-- listings_content -->
	  <div id="listings_content">
		<h1><a href="<?php the_permalink() ?>" rel="bookmark"><?php the_title(); ?></a></h1>
		<p><?php $key="Venue"; echo get_post_meta($post->ID, $key, true); ?></p>
		<p><span><?php $key="Date"; echo get_post_meta($post->ID, $key, true); ?></span></p>
		<p><a href="<?php the_permalink() ?>">more info</a></p>
	  </div>
	  <!-- /listings_wrapper_content -->

	  <!-- listings_thumbnail -->
	  <div id="listings_thumbnail">
	  <?php the_post_thumbnail( 'listings-post-thumbnail' ); ?>
	  </div>
	  <!-- /listings_wrapper_thumbnail -->

	</div>
	<!-- /listings_wrapper -->

<?php endwhile; else: ?>

	<p><?php _e('Sorry, no events matched your criteria.'); ?></p>

<?php endif; ?>

However, when i do that and search by category, it just returns nothing. As soon as I put the code back, it works but not displaying any order, it just shows the posts.
The category list is generated from:
<?php wp_list_categories( 'hide_empty=0&order=ASC&title_li&exclude=3,8' ); ?>
What am I doing wrong?

TIA