The facebook social plugin activity feed found on this page: https://developers.facebook.com/docs/reference/plugins/activity/ does not load in Firefox. I see the feed when I open web pages in Safari, but I get a blank space in Firefox. Below is one example of a website (in the bottom of the blue right bar) where there is a blank/white space instead of a feed. This is happening on multiple sites... in fact I cannot find an example of where the FB activity feed is working properly in Firefox.