There was another topic of this same name, but closed to additional replies :( . However, with the help of a friend I was able to come up with a solution to this problem using the following code:
<?php
$values = get_post_custom_values("$key");
if ( is_array($values)) : ?>
<div class="style">
<img src="<?php bloginfo('template_url'); ?>/images/shared/action_thumbs/<?php print get_post_meta($post->ID, "$key", "true"); ?>" width="200" height="133" border="0" />
</div>
<?php the_content(); ?>
<?php else : ?>
<?php the_content(); ?>
<?php endif; ?>
May be useful to you!