The module allows some space to put some text after the display, it may be that which is causing the empty space.
You can remove it be editing the template, for the default template (file tmpl/default.php) this means removing the lines 34-37:-
<div class="footer_items">
<?php echo strip_tags($params->get('footer'), '<p><a><h1><h2><h3><h4><h5><h6><pre><span><div><img>' ); ?>
</div>
<br style="clear:both" />
For the thumbnails template it is lines 28 to 31.
Alternatively, we will be releasing a new version of the module in the next few days. I can include a test which will only print that part of the output if there is actually something to print, it will take care of the problem for you. If you don't mind waiting a couple of days then you can simply download the new version.
