Help! My ports won't forward!?

I want to forward some ports on my computer for my WOW server, but nothing seems to get them to forward. I am using Apple time capsule as a router and using the ubee comcast modem, and running on a mac. I've tried forwarding ports through static port forwarding in the time capsule, tried forwarding the ports through the IPv6 firewall on the time capsule, and also tried using several third-party programs such as Port Map and Lighthouse, but they don't work any better. I tried to see if my modem was blocking it, but when I went to the config page I can't change anything, it just shows data. My setup is Internet --> Modem --> Router --> Computer and internet voice service. I've tried just about every tutorial on the web, and nothing works. When I remove the static ports and use the Lighthouse program it works a little better, but it still does not open the ports. I have no idea how to fix this and am open to any ideas. Is my modem somehow blocking it? Is there some crucial step I am not following?
Thanks.