I noticed after upgrading NextGEN to 1.4.3 (it may have happened on an earlier upgrade) that the %GALLERY_NAME% placeholder for my Lightbox Effect no longer works. Instead of the rel tag being printed as rel="lightbox[galleryname]" it is now showing up as rel="lightbox[set-111]" (where 111 is the set id).
I use the %GALLERY_NAME% placeholder to make other images in a post navigated seamlessly into the NextGEN gallery images on that post.
An example of the issue can be seen on my blog. If you click the image in the post (it has a rel of lightbox[the-gallery-name]), it will open in a Lightbox. In the past, you would have seen a "1 of 9" caption and a "Next" button that would lead to the first of the NextGEN gallery images. Now you can't navigate between them since the gallery images have a rel with the set ID.