Mine's stopped working too!
I can access the settings page but when I tried to publish to Facebook it went through the motions and looked as though it had worked, but when I checked my Facebook page it hadn't! I then went back into the WP post and there was no 'History' in the 'Social Broadcast' box.
I went into my profile settings and noticed my account was still linked but without pages support (which is how i'd set it up).
I tried to disconnect my Facebook account and reconnect to see if it solved the problem but now getting an error when trying to reconnect...
Error 118 (net::ERR_CONNECTION_TIMED_OUT): The operation timed out.