Till yesterday everything was working fine.
In my website's head there was
<script src="http://static.ak.fbcdn.net/connect.php/js/FB.Share" type="text/javascript"></script>
and links like
<a name="fb_share" share_url="http://mysite.com/url"></a>
were transformed to facebook share plugins.
But now there is a problem - i can't see count of shares in plugin. I sniffed requests a little and the error is:
fb_sharepro_render({"error_code":104,"error_msg":"Requires valid signature","request_args":[{"key":"v","value":"1.0"}
I did not change anything on website and problem still occurs. Any hints?
Edit (probably an answer):
This bug is described here: http://bugs.developers.facebook.net/show_bug.cgi?id=19471
Facebook team response: Thanks for the report. We are looking into this. We recommend to use the like button instead as we are going to deprecate the share button soon. The like button provides you with the same functionality and more ... http://developers.facebook.com/docs/reference/plugins/like/
Also, works solution with request to http://graph.facebook.com/?ids=*.
For example, while issue is not fixed by facebook, you can use a little modified facebook share widget script, it use a graph.facebook.com instead of api.facebook.com/restserver.php.