This came up in another post.
Try this. Enter "about:config" as your url. This will show you all your preferences. Enter add-art as the filter. You should have 2 preferences; currentImageSet and expiration. If not, that might be part of the problem.
If so, the setting for "currentImageSet" should, as of today, be 4. (with each show it will increase) Right-click and select 'modify' then change it from 4 to 3. Open a new window in Firefox (new window, not a new tab) and in a few moments it will tell you add-art has downloaded new images. Restart firefox and test. Let me know what happens.
Basically what I'm asking you to do is check if your preferences are being set, and if so, that the art was downloaded. And then forcing it just to see if that is the problem. We'll see where this gets us.
