I guess I wasn't clear. I am remoting in from a Windows 7 machine to a Windows XP Pro machine via an SSH tunnel. The tunnel is confirmed as correct as using the same tunnel, I can RDP from a Windows XP machine to the Windows XP Pro machine. I also can RDP from the Windows 7 machine via the tunnel to a Windows 2003 Server without any problem. I can also RDP locally from my Windows 7 machine to another machine runinng XP Pro on my local network not using a tunnel.
Somehow, my combination of Windows 7 x64 to Windows XP Pro via an SSH tunnel does not work. It is very frustrating.