Complete clueless how does Facebook OAuth (FBOAuth) work
The message comes from the FBOauth module:

function fboauth_login_user($account) {
  global $user;

  if ($account-&gt;status) {
    $form_state['uid'] = $account-&gt;uid;
    user_login_submit(array(), $form_state);
  }
  else {
    if ($account-&gt;access) {
      drupal_set_message(t('The account with username %name and email %mail ' . 
        'is blocked.',
        array('%name' =&gt; $account-&gt;name,
        '%mail' =&gt; $account-&gt;mail,)), 'error');
    }
    else {
      drupal_set_message(t('The account with username %name and email %mail ' . 
        'is not yet activated.',
        array('%name' =&gt; $account-&gt;name,
        '%mail' =&gt; $account-&gt;mail,)), 'error');

    }
  }

  return !empty($user-&gt;uid);
}


So the user you're trying to log in with has not yet been activated within Drupal. Once the administrator has activated the account, the user will be able to log in using Facebook.

This is the correct behaviour; un-approved accounts should not be accessible just because they've been signed up through Facebook.