This happened to share buttons not using Facebook JS SDK, and using code like :
كود:
<a name="fb_share" type="button_count" share_url="url" href="http://www.facebook.com/sharer.php" rel="nofollow">share</a>< src="http://static.ak.fbcdn.net/connect.php/js/FB.Share" type="text/javascript"></>
It is not known until now if this is a bug need to be fixed or a decision from Facebook to force developers use Facebook JS SDK or like button.
It is very annoying for webmasters and users !