widgets move below main text when comments turned off

I’ve got a weird problem that I can’t seem to figure out.

When I have comments turned on, the widgets appear on the right of the main text, just as they are supposed to do.

However, if I turn off comemnts on a post, the widget moves below the maintext.

This will show you what I mean:

On
http://moonworks.co/uncategorized/comments-turned-on

Off
http://moonworks.co/uncategorized/comments-turned-off

I’ve found that if I add an extra </div> to the single.php page it will solve the problem when comments are turned off, but it totally messes up the page when they are turned on. I add the div here (the final div is extra):

<?php comments_template(); ?>
<div style="clear: both;"></div>
</div></div>

This is the code I have in the single.php file:

<?php get_header(); ?>
	<div id="wrapper">
		<div id="column-setup">
			<div class="postsmain">
			<h1><?php the_title(); ?></h1><p>
			<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
				<div class="content-styles"><?php the_content(__('Keep Reading'));?></div>
			<?php endwhile; else: ?>
			<?php endif; ?>
			<?php comments_template(); ?>
			<div style="clear: both;"></div>
			</div>

			<div class="postswidget">
<?php if ( !function_exists('dynamic_sidebar') || !dynamic_sidebar('Pages') ) : ?>
<?php endif; ?>
			</div>
		</div>
	</div>
<?php get_footer(); ?>