[Plugin: NextGEN Gallery] Arrows underneath the images do not work

http://www.simplyshredded.com/keep-the-drive-alive-20-of-the-best-motivational-and-inspirational-pictures-on-the-web-8th-edition.html

Take a look at this article and click on the arrows underneath the images, etc to go to the “next” or “previous” image.

Any solutions?

Thanks