Visiting your sites in IE8, I don't see the images opening in a lightbox either. They seem to be opening as a new page which only displays a large size of the product image, requiring a click on the back arrow to get back to the product description.
In FF4.0, superfancy.co.uk behaves the same way.
Did you modify/customize the ZLB code? Or have you just removed it at this point?
Bookmarks