What brand & model of modem/router are you using? This might be the unknown firewall mystery. Do you see a brick wall at the bottom of LW's window? Most high speed modems/routers have internal NAT firewalls.
If you had have posted the answers to the questions as requested earlier, then I could have pointed to the problem very quickly rather than a post by post trying to use ESP or look thru the magical glass ball.
BTW it cheeses the regular members off when people are reluctant to post their details. As we can't help much without them. And besides, it's also a requirement as stipulated in the forum rules (as said earlier.) I guess you didn't bother to read them huh! Nobody knows who you are, it's all unanimous so posting these details will not hurt you.