I setup a fresh CentOS 5 install, compile nginx from scratch and am using thin as the rails server.
If I visit the ip adress on the LAN: (for example)
188.8.131.52 I get the website not found error.
However, I can ssh into the machine. If I use links to visit the ip address, I get the landing page.
system-config-securitylevel and then was able to change the security settings to allow incoming connections.