Well, that was super simple to figure out!!
copy the /includes/modules/pages/product_info/jscript_lightbox.php file to the appropriate /modules/pages folder for the page in question.
For a future release, there are at LEAST these three places this should be copied to that will affect every installation (because they are part of the core code):
/includes/modules/pages/product_reviews
/includes/modules/pages/product_reviews_info
/includes/modules/pages/product_reviews_write
Hope that helps!
- Steven