Amazing discovery: jwchat won't work at port 80 but works at port 8800!

I was struggling for serveral weeks to get jwchat work at http ports. I picked up a port of 5225. It worked. Then I changed it to port 80. It would not work! Then I changed it to 8800. It worked.
In my previous posting, I said jwchat is not working with Apache2. That is wrong. The fact is jwchat won't work at port 80.
Now my chat server at http is working at http://breakevilaxis.org:8800
Also it works at https://breakevilaxis.org

Probablly there are some tricks that I have to run as apache instead of as root.

This is the configuration:

AddDefaultCharset UTF-8
ProxyRequests off
ProxyVia off
ProxyPass /http-poll/ http://127.0.0.1:5280/http-poll/
ProxyPassReverse /http-poll/ http://127.0.0.1:5280/http-poll/