Unable to connect to XP machine via RDP

I have a new desktop and previously had no problem doing RDP to my old desktop, but now I receive messages that the remote computer cannot connect to the host (my new desktop).

I properly have port forwarding set so port 3388 goes to the IP address of my desktop.

The only thing I can think of is a firewall issue. I turned off Windows firewall…and do not have any other firewall installed. BUT I do have Norton Anti-Virus installed (not Norton IS, just Anti-Virus). BUT when I look at the Norton Protection Center, it says incoming firewall is secure…even though I don’t have Norton Firewall.

What do I have to do to connect via RDP to my desktop?

Thanks,
Steve