Lightbox changed the way it was working

Hello.

In the last few days my Lightbox has changed the way it functions.
It used to be that when you clicked the thumbnail on the item page you would see the item grow larger and appear in a box over the darkened web page. It would have an X for you to close the box.

Now, when you click it instantly goes to a new web page and show a large version. There is no X so you have to back page on the browser.

I checked the store setting in the Presentation tab and it's set to Lightbox as it was originally.

Any ideas?

Here's the link to one of the item's pages: http://www.neal-fox.com/buy-stuff/stuff/big-sandwich/