It appears there is a JavaScript error on the page located at line 95 character 23.
TypeError: $ is not a function: var $active = $(‘#slideshow a.active’);
Deleting the offending script removes the error and allows other JavaScript to function including the version of Fancybox that ships with RPS Image Gallery.
We are not sure where the offending script originates, whether it is part of another plugin or the theme you are using. Recent updates to other plugins or your theme might provide a clue.