I've installed NextGEN Gallery Version 1.8.0 hoping to see the following great feature working, as written in the plug-in website:
I’ve added the support for XML Sitemaps for images. You just need to install the great plugin from Yoast : WordPress SEO
The created image sitemap list urls with zero images, in the format:
website/ngg_tag/name of an image tag/
Once you click on one of these urls you see a link to one or more posts which really has no images. Actually there are always 4 images in the left bar (last uploaded and a random image) , and maybe this fact has confused Yoast WordPress SEO.
Anyone else with the same problem?