I'm not sure what happened here, but for some reason my NextGEN Gallery pages link directly to the original image instead of the nifty pop up with the forward and back buttons. I'm running the latest version 1.7.4, and just changed my theme (which required YAPB). However, even when I turned off the YAPB plugin and reverted to the original theme, the gallery pages still went to the original image.
Here's the main gallery page: http://www.jasonkuo.com/blog/?page_id=14
And here's the NextGEN code I'm using on that page:
Weddings [album=1 template=extend] Events [album=2]
That's it! Any help would be much appreciated!