I having the same ppoblem. The thumbnails images appear, but when ‘click’ the image is redirected to direct image link (ignoring Fancybox). I identify the problem, is with the JIGOSHOP plugin. his plugin loads another version of Fancybox. If i disable JIGOSHOP, the images load correctly with fancybox.
How can I disable one of Fancybox?
Sorry my bad english.