Of course, now I see how you have a problem with hardcoding in the lightbox.js file

Where it says:
Code:
//
//	Configuration
//
var fileLoadingImage = "includes/templates/template_default/images/lightbox/loading.gif";	
var fileBottomNavCloseImage = "includes/templates/template_default/images/lightbox/closelabel.gif";
There's no easy way of doing that without hardcoding. I suppose the best way to work this if you want to conform as much as possible to the templating scheme of zen without creating a lot of work... is to do this:
Code:
//
//	Configuration
//
var fileLoadingImage = "images/lightbox/loading.gif";	
var fileBottomNavCloseImage = "images/lightbox/closelabel.gif";
and move the two image files to the main image directory.

All just suggestions!

- Steven