[CentOS] httpd: "internal dummy connection"

On my Centos 2.5 web server, in  /var/log/httpd/access_log,
I saw several occurrences of:

   new.mydomain.net - - [11/Feb/2009:14:34:58 -0500] "GET /
      HTTP/1.0" 403 - "-" "Apache/2.2.3 (CentOS)
      (internal dummy connection)"

I have never seen anything like this before over many
years of watching my logs.  I presume it failed because
my named virtual host does not have "new...", if for
no other reason.

What is it?  Why do I have it now, and not before?

Thanks for your advice.
Mike.