I have nextgen gallery installed and have an album of galleries on a page. When I click on a gallery, the lightbox type behaviour is activated but it is a different interface than the usual lightbox behaviour which I get if I click image again. I assume that the first light box behaviour is a next gen interface and has double arrows for navigation at the bottom of it.
The normal lightbox you can see under the nextgen lightbox. This is very hard to explain so I have taken some screenshots
Not sure why these links didnt show up and no preview here so links are a couple of posts down