Ubuntu Servers :: Just Installed Ubuntu 9.10 - But Port 80 Blocked - Can Not Find Server/location

I installed Ubuntu 9.10 and tomcat 6 java servlet container. I am trying to run the tomcat server on port 80, so I edited tomcat's configuration file (server.xml) and changed the default port from "8080" to "80". I launched tomcat server, went to my browser and entered:[url], but it says can not find server/location. Then I edit the server.xml and revert back to port "8080" and then enter: [url] and everything works fine. So my guess is some other service is taking up port 80, but I would think not, since I just installed Ubuntu and made sure apache isn't installed or running.

So I went to "System" --> "Administration", then choose "Network Tools". I then executed Netstat and did not see anything taking up port 80, but I do see port 8080 taken (assuming it is the tomcat server). Then I also did a Port Scan and entered my IP number. Again, I don't see port 80 taken, but do see 8080 being used.

I had a winxp laptop computer behind home wireless and was running tomcat 6 server fine with it, but it over-heated and died recently. So I got a used laptop and just installed Ubuntu 9.10. I have not changed my wireless router settings. It is the same as before. So I have ruled out my home's hardware/network equipment.

So here now I sit, wondering what is up?

For security reasons, is port 80 initially blocked by Ubuntu for some reason? Is there something I have to do beforehand to free up port 80?