overriding node form for cck in og

Hello, I am trying to theme the add/edit form for a content type that is only added through og using the tutorial linked here: http://drupal.org/node/101092

However, the override doesn't affect the add form, as the arguments in the url it uses to override the form aren't there when added from og (it uses ognodeadd?type instead of node/add/type). Below is the code that normally overrides the add form:

if ((arg(0) == 'node') && (arg(1) == 'add') && (arg(2) == 'project_storyboard')){
  function phptemplate_node_form($form) {
    return _phptemplate_callback('node-project_storyboard-edit', array('user' => $user, 'form' => $form));
  }
}

I tried changing it to this to try and get it to affect the ognodeadd form at all, however it isn't working:

if (arg(0) == 'ognodeadd') {
  function phptemplate_node_form($form) {
    return _phptemplate_callback('node-project_storyboard-edit', array('user' => $user, 'form' => $form));
  }
}

What do I need to do to modify the argument it's going after to get this override to work?