Magnifying images not working in Firefox (Mac OSX)

When I click an image to enlarge it in the shop the screen dims but no image pops up, works in Explorer and Safari but not in Firefox. Tried on different computers and the problem is on all of them.

Here is a thread which already talks about that problem:
www.hikashop.com/fr/support/forum/4-how-...ng-with-firefox.html