Out of curiosity, why aren't the Joomla! publish types a set of constants defined in a common location?
e.g. in ControllerAdmin::publish() :
array('publish' => 1, 'unpublish' => 0, 'archive' => 2, 'trash' => -2, 'report' => -3);
I've seen these numeric values used elsewhere in the JGrid as well.