Causing Thousands of Pages to be Created

I recently installed the plugin on one of my newest websites because it has worked great on a couple other sites I have. But, there is some kind of issue that is causing between 6000-9000 additional pages created and added to a site that originally had about 15 pages.

Here is an example of one of the many pages that it is creating. I have searched the support forum but couldn’t seem to find where the same issue happened, but I may have overlooked. Could you help me with this?

http://www.forcefieldpaintshield.com/gallery/nggallery/page/2/contact-us/paint-protection-film-ppf- dallas/contact-us/slideshow/contact-us/paint-protection-film-ppf-dallas/contact-us/contact-us/

http://wordpress.org/plugins/nextgen-gallery/