The OG:TITLE contains site name

The most recent dev version now contains only site name in the og:title property.

function fb_social_init() {

  // Add simple OpenGraph metatags
  $data = "";
  if (variable_get('fb_social_opengraph', 1)) {
    $content = drupal_set_title();
    $content = $content ? strip_tags($content) : variable_get('site_name', 'Drupal');
    //add fbml header meta information
    $data = '<meta property="og:title" content="' . $content . '"/>' . "\n";
    $data .= '<meta property="og:site_name" content="' . variable_get('site_name', '') . '"/>' . "\n";
    // @todo maybe look for images/imagefields uploaded/attached to the node ?
    // $data .= '<meta property="og:image" content="http://ia.media-imdb.com/rock.jpg"/>';
  }

It looks like the drupal_set_title is returning a null string. Or it can be the drupal_set_title which is returning the site name. In any case it's a causing a major problem for our user.