When you have javascript errors on the page then most of your javascript related widgets, plugins, modules will stop working entirely.
I checked your site and your receiving an additional error,
jQuery("form.product_form").livequery is not a function
[Break On This Error] jQuery("form.product_form").livequery(function(){
wp-e-c...=3.7.59 (line 143)
jQuery("a[rel^='prettyPhoto'], a[rel^='lightbox']").prettyPhoto is not a function
[Break On This Error] "theme": 'light_square' /* light_rou...uare / dark_square */
The second error is usually always caused from another version of jQuery being loaded in the page. In your case the version being loaded from google.
I would make sure and correct that before continuing scoc, see my previous post.