Bug discovered for MarketPress

Hi, i discovered a bug regarding the MarketPress plugin.

On an individual product page ( for example here: http://www.sagaegroup.com/store/products/sample-product-2/ ) when I click on the image, 2 lightbox appears. So when i close 1 lightbox, I need to close another lightbox in order for the reveal the product page again.

How can this bug be fixed?