Duh, I found out what it was, although, I should have sussed this a week ago, when I was banning the nameserver IP - my backend.php script ( hack from here ) that places last 10 comments, in an RSS newsfeed, reported 10 lines of No title and no post. Unbanning the IP, fixed this - then I noticed that the guest was on the backend.php and it clicked. An rss newsfeed has to update every half an hour, so thats why this "guest" appeared.