The <object> tag contains invalid width and height attributes.
<object id="prezi_' . $id . '" name="prezi_' . $id . '" width="' . $id . '" height="' . $id . '">
should be:
<object id="prezi_' . $id . '" name="prezi_' . $id . '" width="' . $width . '" height="' . $height . '">
