Images not displaying

I can't see the preview of images on /b/ when I use firefox. Works fine with internet explorer, and works fine on every boards besides /b/.
I have disabled the adblocker and the 4chan tool, with no effect whatsoever.

Other boards work very well. Anyone has an idea as to what causes this problem, and how to solve it?

Tools -> Options -> Content -> [Exceptions] next to "Load images automatically" -> Remove "img.4chan.org"