I currently use Mantra 18.104.22.168 and have a problem with the NextGen Gallery. I can download pictures (no zip) but they are never displayed, neither full size or thumbnail. These pictures are all in JPEG.
I already uninstall and install back the pluggin but still the same problem. You can see it there : http://know-mansland.com/2013/03/10/essai-galerie-lalbanie/
So I am wondering if it could come from a compatibility between Mantra and NextGen!?
I would be glad to know if anyone has already met this situation? Or if maybe, you have a solution?