Newest versions of wamp and SigPro.  Click on a thumbnail and you get 2 lightbox images, one on top of the other.  Have to click outside of each image to get back to the thumbnails.  I am using Front Page Slide Show, SigPro (SlimBox) and Lightfast template.  This newbie doesn't know if it is proper, but this fix worked for me:

Modify popup.php which can be found here:
jw_sigpro/popup_engines/mootools_slimbox/popup0.php

remove line 17 which is <script type="text/javascript" src="'.$popupPath.'/js/slimbox.js"></script>

Don't forget to save an original copy in case it doesn't work for you.