i use win xp pro w/sp 2, and this is my problem: i created a vpn with a friend of mine, everything is perfect, except for one thing: i can connect to him (i mean, he acts as server) but i cannot be the server, when he tries to connect to me, he gets a connection refused error.. another example, i can play games as client but not as host... i can use a software for remote desktop (VNC free edition) and i can see his desktop (act as client) but he can't see mine (he gets timeouts and connection refused errors)...
i shutdown the firewall, the antivirus, and lowered internet security in windows, but i never managed to make it work!
help...! i don't know how to fix this issue!

thanks in advance!