I think the most likely answer is that Q2A can't retrieve information on the user from the Facebook API, because your PHP configuration does not allow retrieval of content from remote URLs via file_get_contents() or curl.
The function qa_retrieve_url() in qa-base.php is used to retrieve the content from the Facebook API. You could modify that temporarily to echo strlen($contents) to the browser just before the end of the function, and then see if a zero appears on the page - that would mean no content could be retrieved.