htttp port changing problem

I was wondering if someone can help me. Currently I have Fedora Core version 3 and due to my internet provider I can not use port 80. I have two servers; one is setup for http port 8085 second 8090 and is functioning just fine. I did upgrade to Version 6 and now I am unable to use any port but the default which is port 80. If I change it to any port but 80 service will not start. I am having the same problem with version 4 and 5. Tried Centos 4.0 and is giving me the same problem.

Thank you for your help.

Mike,