Margin-bottom @ thumbnail in post loop

I have a thumbnail set up next to the excerpt summery text of the posts.
All is well, but underneath the thumb there is a padding/ margin of 7px.
I can’t get rid of it. The crazy thing about it is that when I put text instead of the image code the padding is gone….
I can’t yet put the site online through restrictions, but hopefully someone can help me with this.

Image of post with thumbnail
7px margin or padding

Image of post with text instead of image
no margin or padding

Code of the loop

<div id="totaal-post">
	<ul class="post-not">
    <li>
    	<div id="post-summary">
    	         <?php $thumb = get_post_meta($post->ID, "thumb", true);
				 if ($thumb != ""){ ?>
				 <?php the_excerpt(); ?>
				 <?php } else { ?>
				 <?php the_content(); ?>
				 <?php } ?>
    	</div>
   		 <div class="post-thumbnails">

		 <?php the_post_thumbnail(array(120,120), array('class' => ''));?>
         </div>
	</li>
	</ul><!-- .posts-quick -->    

        <?php if ( is_archive() || is_search() ) : // Only display excerpts for archives and search. ?>
        	<?php else : ?>
			<?php endif; ?>
    </div><!-- #archive-posts -->

Code of the CSS

#totaal-post{
	border:solid #d4d4d4 1px;
	margin-bottom: 20px;
	pading: 0;
	background: url(images/post_bg.gif) repeat-x left top #f1f1f1;
}

.post-not{
	list-style: none;
	margin: 0px;
	padding: 0px;
	overflow: hidden;
}

.post-thumbnails {
	float:left;
	width:120px;
	background-color:#F66;
	text-align:center;
}

#post-summary {
	width:498px;
	padding: 10px;
	float:right;
	background-color:#FFC;
	line-height: 1.3em;
	color: 000;
}