I had the same problem. Fixed it my removing or adding a trailing “/” on the facebook app settings.
This is a nice plugin among those I tested, but now I’m directly modifying my theme files to include the fb comment box.
What would be ftw is if there is a way for non-facebook users to comment along-side. It used to be possible before facebook did removed that feature.
cool. that’s exactly what i need.
btw where can we find a complete list of hooks and filters to use? the wordpress codex seems incomplete.