wp_page_links() not functioning correctly

I picked up a job as the maintainer of a few websites recently, and my client has emailed me with a pretty weird problem.

He was trying to use the <!–nextpage–> tag, and the pages are generated and split, but when you select a page number, the first page loads no matter what the number given in the url is.

The client updated some plugins before this happened. I asked for a list, and checked if one of them caused the issue, but none returned functionality. This seems to have affected not just new pages, but also pages published before the updates.

Example here:http://www.bmxunion.com/blog/photogallery/banned-jam-photogallery/