[Plugin: NextGEN Gallery] NextGen lightbox stopped working

I’m setting up NextGen on my site, and I’m almost done, but all of a sudden lightbox won’t work when I click on images in the image list in a post.

I’ve used NextGen before without any problems, and I’ve certainly never run into this before. I reset all plugin settings but it didn’t fix the problem.

Lightbox was working when I first set NG up on the server, and it works in other blogs on the same server. I know there’s the Javascript I have to add to get the Slideshow functions to work, but does that have anything to do with the lightbox effect? Why would it be disabled?

Any help would be awesome.