Facebook Comments Not allowing to post anonymous comments

I have recently integrated facebook comments on my photo galle开发者_运维问答ry. I am facing a problem with fb:comments. The user is not allowed to comment if he is not logged in. The user is shown the screen for anonymous comments but will not be able to post the comment. when i check the social plugins of facebook, surprisingly it is not working there too. Please help me with this.

You might want to use the Facebook developer forum for this one. Others seem to be having the same problem. http://forum.developers.facebook.com/viewtopic.php?pid=226160