next image in pagination

I have a problem, I created my gallery with pagination, but the last image of the first page it does not go to the next image that is on page 2, and the same event happens on the first image of the second page it does not go to the last frame of the first page. Its set up, the next and previous button link goes to have pagination? Does anyone know to fix this problem.

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