Latest version 42.0 of Firefox broke this. Inside disqus comments people link to twitter posts. The image from those posts no longer show up. There is just an empty space. I found that I could make it work again by going into the Firefox Privacy settings and turning "remember history" back on. When I use "never remember history" the twitter "image" doesn't shot up. Here is an example" http://www.17-seconds.com/2015/11/2015-11-08-quizas.html#comment-2348980476 It used to display the twitter box even with "never remember history" selected.