What is going on?

[Trucast]

I appologise if this has been posted before, but I'm having serious problems hosting games.

I can connect to peoples games no problem, but non of my friends can connect to my games. I have opened numerous ports, disabled countless firewalls and stopped software which may be the cause but still, I cant connect to Some games, and some people cant connect to me.

Any ideas would be greatly appreciated.

Thanks!