I know that's what it is... well, at least now I do.
I set the listen directive in the httpd.conf to the second ip on the interface. That certainly will stop it from responding on 127.0.0.1.
I was trying to separate ispconfig from the rest of the web sites by giving ispconfig port 80 and 443 on the primary IP, and httpd 80 and 443 on the secondary ip. I guess I chose the wrong way to do it... Do you have a better solution for me? (I need to run ispconfig on 80 or 443 to get by firewalls)