Originally Posted by
HaTaX If you're running on Win vista or 7 the firewall may be ruining your fun. You really only need one port forwarded, 5900 is the default port it listens on. You can change to 5901, 5902, etc for other computers you want to access from the outside. You only need to forward TCP traffic on port 5900 (or an alternative that you choose) to the PC to be able to gain access.
Can you connect to this PC inside the LAN with a VNC client? Taking the firewall out of the mix will help you determine that you're looking in the right area.