[Plugin: NextGEN Gallery] Galleries no longer working — help!

I have really loved this plug-in but it has stopped working.

I can create a gallery and insert it into a page or post but when you click on the thumbnail, it directs it to a full page, not longer a lightbox or popup.

My website is http://bittenbyazebraphotography.com

Any help would be appreciated.

http://wordpress.org/extend/plugins/nextgen-gallery/