I’ve noticed this, too. There seem to be some glitches when propagating TV’s down through folders. Sometimes it works and sometimes not.
I used SuperFast and that worked fairly well. A little more cumbersome for deep folders, but at least it is a little more flexible, too.
$this->fields['id']=$modx->db->insert(&$this->fields, $tablename);
$modx->db->update(&$this->fields, $tablename, "id=$id");
$this->fields['id']=$modx->db->insert($this->fields, $tablename);
$modx->db->update($this->fields, $tablename, "id=$id");