getting tomcat to respond from internet

I'm having a problem getting Tomcat 6.0.16 to work as a standalone internet server. It's running behind an Actiontec router. It works perfectly inside the network. I tried the preconfigured version of Tomcat that sets its port to 80, after having tried doing the same thing manually in the server.xml. The router is set to forward ports 80 and 443 to the computer's fixed internal IP address. I've tried with the firewall both off and on.

I have a nicely working servlet and a hello.jsp at webapps/SpeechServer. Everything works great from inside the network. If I put the address http://127.0.0.1/SpeechServer or http://192.168.0.10/SpeechServer in a browser, it opens the hello.jsp at that location. But if I put the external IP in (e.g. http://71.212.221.216/SpeechServer), Firefox gives me a 404 not found error. Putting in http://71.212.221.216 brings up the router, as one might expect (I might have thought the router would forward that request to the server, since it's http on port 80, but then how would one ever reconfigure the router?). I've also tried having the router forward the port 8080 (its default) to the local server address, then putting in http://71.212.221.216:8080/SpeechServer, but that fails, too.

I know lots of people are successfully using Tomcat as an internet server as I'd like to. I've done everything that has been given in various instructions on the web for setting up Tomcat for this purpose, but it's not working. What else could be wrong?

Thanks!

Hutch