Using ACL in custom Module - the start

Hi there,
based on the example I started to build an custom acl module. The acl entries are build in the db, that is working, but I have one question left.. for the first :-)

I use devel to show the realms of a node. I'm wondering, why my custom acl rule is not shown up in the debug blocks. This is my code so far. You see it's taken from the example. I could imagine, that I have to use "hook_node_grants()" and some more hooks to make this working?! ACL is not creating a realm automatically?

unction vf_acl_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
  switch ($op) {
    case 'update':
    case 'insert':
      
      if($node->type == 'blog_crosspost' || 'blog_pm' || 'blog_comment' || 'blog_private_post') 
        {
        //dsm($node);
        // ???
     /*   if($acl_id = acl_get_id_by_name('acl_example', $node->nid)){
          //we start of with a clean slate. We don't want strange users to be kept in the system
          //since we only add users once in a while this does not impact user performance
          acl_delete_acl($acl_id);
          
          //we do not have a function that allows us to remove all users at once so this is a good future option
        } */
        //we create an ACL that we will use on every file or node that is in someway attached to this node
        //we decide to name it to the id of the node since the name of the node can change in an other phase.
        //dsm('creating a new acl for '.$node->nid);
        
        acl_node_access_records($node);
        
        $acl_id = acl_create_new_acl('vf-moderator','node' .$node->nid);
        // gid 
        $gid = current($node->og_groups);
        //get all moderators from the group
        $group_moderators = vf_acl_group_moderators($gid,3);
        
        dsm($group_moderators);
        //make our array unique
        $group_moderators = array_unique($group_moderators);

        //assign these users to the ACL
        foreach($group_moderators as $uid) {
          acl_add_user($acl_id, $uid);
        }
        //assign the ACL to the node (View Yes, Write No, Delete No)
        acl_node_add_acl($node->nid,$acl_id,1,0,0,0);
       
        //assign the ACL to the nodes (View Yes, Write No, Delete No)
       // foreach($nodes as $nid) {
        //acl_node_add_acl($nid,$acl_id,1,0,0,5);
        //}
      }
    }
}

/**
 * Used by the ACL module.
 */
function vf_acl_enabled() {
  return !content_access_disabling();
}


/**
 * Implementation of hook_disable().
 */
function vf_acl_disable() {
  teytel_permissions_disabling(TRUE);
}

/**
 * Remembers if we have disabled access.
 */
function vf_acl_disabling($set = NULL) {
  static $disabling = FALSE;

  if (isset($set)) {
    $disabling = $set;
  }
  return $disabling;
}