I ran into this problem the first time I tried to install SG in an older domain. It ended up requiring some type of hack/fix.
This is many version later, however, and I just tried installing it on a new domain, and I just cannot seem to get any images to open in a lightbox -- single images or gallery images. I don't need a separate page and all that. I just want it to open in a lightbox and allow people to post FB comments.
I do use JIG, but I want this available for all content images -- including JIG.
I don't really know what other details I can provide. Any guidance in this regard would be greatly appreciated!