You are right.. Additional images management is part of core Zen Cart fucntionality, and LB only works WITH this. Might help you (and others reading this thread) going forward to read up on how Zen Cart manages additonal images..

Image names are how Zen Cart "recognizes" and associates images with a product.. These FAQs may help..

Why am I seeing images for other products on my product pages?

How do I add multiple images to a product?

Quote Originally Posted by ScriptJunkie View Post
Update

ScriptJunkie Posted
Discovered that LB does handle my gift certificate images the same way it handles my other product images - I was just unable to see that in action because my other test product images don't share similar file names as the gift certificates do. (i.e. GV25.png and GV250.png for $25 and $250 gift certificates).

The issue was not caused by having GV25.png and GV25_LRG.png in the image and _LRG image folders respectively. It was caused by having both a GV25.png and a GV250.png in the main image folder, and a GV25_LRG.png and a GV250_LRG.png in the _LRG image folder.

End result: If product images are in the main image folder, and their "zoom" versions are in the _LRG image folder, Zen LB will handle them appropriately, so long as different product images do not share a similar file name.

Wanted to clarify for other posters that the issue here was not a Zen Lightbox issue, but rather a file naming issue.

Thanks Daniel, for pointing me in the right direction with your advice