Random Posts is Duplicating Thumbnails

Hi,

I’m trying to hard code a random posts area in my sidebar. I got this from the codex:

<li>
		    <h2>random posts</h2>
			<ul>
			<?php $rand_posts = get_posts('numberposts=4&category_name=blog&orderby=rand');
				foreach( $rand_posts as $post ) : ?>

			<li><div class="sidebar-post" id="post-<?php the_ID(); ?>">

			<?php if ( has_post_thumbnail() ) { } else { } ?>
			<?php the_post_thumbnail(); ?>

			<div class="blog-post-text">
			<h3><?php the_title(); ?></h3>
			<?php the_excerpt(); ?>
			<p><a href="<?php the_title_attribute(); ?>">view now...</a></p>
			</div></li>

			</div>

				<?php endforeach; ?>
				</ul>

		</li>

The problem is that each post is picking up the same thumbnail (the first post’s thumbnail). You can see this at http://pixelbang.com/travel in the bottom of the sidebar.

Would anybody be able to help me out?

Thanks,

Nick