Field "Node: Has new content" outputs link to "node" instead of the node

I've a view of blog posts with the "Node: Has new content" field, set to output as a link.
In some cases this is output as a link to "node" instead of "node/nid".

I'm finding this hard to reproduce, as on my site it's intermittent -- seems to be showing for registered users but not the admin user, which makes no sense.

The code that makes the link is in views_handler_field_node.inc render_link():

      $this->options['alter']['path'] = "node/" . $values->{$this->aliases['nid']};

Debug output shows that:
- $this->aliases['nid'] is history_user_nid, which is correct
- $values->history_user_nid is empty.

history_user_timestamp is also empty, which suggests looking at the query that the join to history_user got no results:

	

SELECT node.nid AS nid,
   node.title AS node_title,
   node_revisions.teaser AS node_revisions_teaser,
   node_revisions.format AS node_revisions_format,
   history_user.timestamp AS history_user_timestamp,
   history_user.nid AS history_user_nid,
   node.created AS node_created,
   node.changed AS node_changed,
   node_comment_statistics.last_comment_timestamp AS node_comment_statistics_last_comment_timestamp,
   node.sticky AS node_sticky
 FROM node node 
 LEFT JOIN node_revisions node_revisions ON node.vid = node_revisions.vid
 LEFT JOIN history history_user ON node.nid = history_user.nid AND history_user.uid = ***CURRENT_USER***
 LEFT JOIN node_comment_statistics node_comment_statistics ON node.nid = node_comment_statistics.nid
 WHERE (node.status <> 0) AND (node.type in ('blog'))
   ORDER BY node_sticky DESC, node_created DESC

So if there's no history for the current user, why is the field showing?
I wondered if this might be the same problem as http://drupal.org/node/408414, but changing the order of the nodes in the view so the one with the updated mark came first instead of last didn't change the outcome.