[Plugin: NextGEN Gallery] No effects

Would help to havea link to a page with the issue. And what effects you are looking for.

I only see the single image uploaded into a Nextgen gallery. Why not use the Shadowbox JS plugin? Simpler and then will work with your other pictures not uploaded into a Nextgen gallery.
But in Nextgen make sure in the Gallery/Options you have the javascript setting for thickbox or lightbox.