Too many node_access-records

Thanks for your quick response, I just realized I had to add some more information..
This is my problem: #1360896: Rebuild permissions generates Fatal error: spl_autoload(): Class Database could not be loaded in database.inc on line 2412
However, that does not occur when only NA_UR is enabled, but it did make me look at the node_access table better than before.
NA_UR works very fine after the updates from last summer.

I updated to latest version.
I have no other access-modules enabled.
I have a content type with 1 field relevant for NA_UR. These are the settings:

Grants for referenced users = View
Grants for author = Empty
Grants for all users = View
When to set grants =  When the user reference field is in use
VIEWS - NODES TO AFFECT = None

And this is what is generated - a line for each node:

nid  gid realm grant_view grant_update grant_delete.
10195	0	all	1	0	0
10196	0	all	1	0	0
10198	172	nodeaccess_userreference	1	0	0
10200	0	all	1	0	0

This seems normal behaviour by node.module:
node_save() calls node_access_acquire_grants(). Here, a default value is inserted for every node that is not affected by a node_access-module.
node_access_rebuild() generates one (1) record in node_access table if no access-control module is implemented. array('nid' => 0, 'realm' => 'all', 'gid' => 0, 'grant_view' => 1, 'grant_update' => 0, 'grant_delete' => 0,)

Just for confimration ad reassurance, if you have an installation with nodes that are not affected by any node-access module, are they still in youd node_access-table?

Thanks for your support.

function node_access_acquire_grants($node, $delete = TRUE) {
  $grants = module_invoke_all('node_access_records', $node);
  // Let modules alter the grants.
  drupal_alter('node_access_records', $grants, $node);
  // If no grants are set and the node is published, then use the default grant.
  if (empty($grants) && !empty($node->status)) {
    $grants[] = array('realm' => 'all', 'gid' => 0, 'grant_view' => 1, 'grant_update' => 0, 'grant_delete' => 0);
  }
  else {

    // Retain grants by highest priority.
    $grant_by_priority = array();
    foreach ($grants as $g) {
      $grant_by_priority[intval($g['priority'])][] = $g;
    }
    krsort($grant_by_priority);
    $grants = array_shift($grant_by_priority);
  }
  node_access_write_grants($node, $grants, NULL, $delete);
}

Yes every node is in the node access table

Nice, that is reassuring..

, even with no node_access modules

But that is not my experience...