Well, if you have a big blank area that is good. It means the widget is loading. If you right-click in the blank area it should say something about your flash options (just to confirm its loaded the flash)

I think your XML is kinda broken. The example I posted is from a working one.

I'd try copying that and editing it as closely as possible to use your own info. The way it's set up is so you can have a customer go to your detail page where the add-to-cart button is when one of the pictures is clicked.

I don't think the "lightbox" param is the same Zen Lightbox you are thinking.