Hi
I never got a solution on my problem which to get previous/next buttons to work in a custom field.
I discovered that by putting in lightbox[gallery-1] for the rel works ONLY IF I do all of the images at once (and if I don’t go back to check).
What I was doing was putting the rel value in for 2 of the images, publishing, checking and then –seeing that it worked–I went back to finish. By doing that, it triggered a bug and the whole thing broke: title got filled with words “gallery-1”, and “> was inserted before image, and previous/next would not work.
I’m writing now to offer this temporary solution to anyone who might have the same issue.
I would LOVE to keep using this plugin and hope that this gets resolved.