How to create views argument to show users of a specific group type

I am sorry to be cross posting this. I have previously asked this question in the post-installation forum to avoid overburdening the views issue queue but have been unable to resolve my difficulties, http://drupal.org/node/631236

I would like to be able to list the users in groups of a specific group type only and restrict the view to users in the group. I believe this is an issue that requires proper use of arguments rather than a relationship, but I may be wrong.

When I use the validator Group node I am unable to specify a specific group type.

I have tried using the php code validator without success using the following:

global $current_view;
print $current_view->args[0];
$gid = arg(1);
    if (og_is_group_member($gid)) {
      $currentGroup = og_get_group_context();
      $groupType = $currentGroup->type;
      if (!strcmp($groupType, "group_typename"))
        { return TRUE;}
    }

I am not sure if the php code I am using is wrong or if the php code validator is not working for this along the lines of another item in the issue queue http://drupal.org/node/616402

This is very important to me and I would appreciate any help to resolve it.

Thanks,

Izzy