in the gallery index page, try changing:
echo '<a href="' . $gallery['images'][$i]['fullsize']['url'] . '" rel="lightbox-pg' . $random . '" name="<strong>' . str_replace('"', '\"', $gallery['images'][$i]['title']) . (strlen($gallery['images'][$i]['title']) > 0 ? ':' : '') . '</strong> ' . str_replace('"', '\"', $gallery['images'][$i]['description']) . '"><img alt="" title="' . $i . '##' . str_replace('"', '\"', $gallery['images'][$i]['title']) . '##' . str_replace('"', '\"', $gallery['images'][$i]['description']) . '" src="' . $gallery['images'][$i]['thumb']['url'] . '" width="66" height="70" alt="test" /></a>';
to:
echo '<a href="' . $gallery['images'][$i]['fullsize']['url'] . '" rel="lightbox-pg' . $random . '" name="<strong>' . str_replace('"', '\"', $gallery['images'][$i]['title']) . (strlen($gallery['images'][$i]['title']) > 0 ? ':' : '') . '</strong> ' . str_replace('"', '\"', $gallery['images'][$i]['description']) . '"><img alt="" title="' . $i . '##' . str_replace('"', '\"', $gallery['images'][$i]['title']) . '##' . str_replace('"', '\"', $gallery['images'][$i]['description']) . '" src="' . $gallery['images'][$i]['thumb']['url'] . '" width="200" height="140" alt="test" /></a>';