I also had a problem with NextGen and 2.8.4, but have fixed it. My galleries would show up, but the Thickbox effect didn’t work. Instead, it linked directly to the image file with no effect.
The problem had to do with Thickbox and jQuery in WordPress 2.8.
Thickbox loads in the footer section in WordPress 2.8, that should be right before the closing body tag. And yes, loads of themes are lacking the wp_footer() function call.
The original theme I’m using called this correctly, but in modifying the theme, I left the wp_footer() call out on the pages I was using NextGen. Adding that in, just before the final body tag, fixed the problem.
Note: This was with the latest 1.3.6 version of NextGen.
Another Note: This only fixed the Thickbox effect. The Lightbox and Highslide effects do not work for me. (I don’t know why not or when they stopped working, but I don’t use them anyway.) The Shutter effect worked even before I made this fix and still works now. (I don’t know why this is so, either.)
Hope this is helpful.
