If you're using Norton Firewall, then disable XP's firewall otherwise it will cause problems. It will also give you less security with 2 softw firewalls running simultaneously. There's been many a person on this forum who had that problem. MS also don't recommend running 2 firewalls as do most other firewall vendors.

Your actiontec, is it a modem or router. Have you enabled UPnP settings on it. If it doesn't have that ability then manual port forwarding is the way to go. See Connection problems? Check here first! (click on link) & find out if your device has UPnP abilities or not. You can find it by using your browser to access it & see what options it has. If you can't find universal plug & play option, then manual port forwarding is what you should do. Go to that section of the link above.