Woocommerce Product Gallery problem

Hi!
I have a problem with the product gallery of the woocommerce plugin.
When I click on one of the images, it loads directly into the current window instead poping up a lightbox or similar, like it did in the theme demo.

My site: http://runemarkstudio.com/product/dialogue-editor/
Demo site: http://skywarriorthemes.com/oblivion/product/premium-quality/
The images doesn’t appear like in the demo. Why is this? Am I missing something?