Open Navigation Menu Item In Lightbox, Using Venobox

Venobox is a great plugin and very easy to use.

But I want to know how to use Venobox to open a menu item in a lightbox. I have tried setting the class of the menu item to “venobox” but that does not seem to work. It starts, but seems to get stuck loading the page that should be display inside the lightbox.

How do I achieve this please?

The page I need help with: [log in to see the link]