This is a somewhat obscure question, and unfortunately the companies
that sell the software involved don't seem to be able to help.

I am running Windows 2000 Professional at home, with all of the latest
updates and service packs.   I am running an SSH server on this
computer. The implementation of SSH I am using comes from bitvise
(www.bitvise.com), which is easy to use and only costs $40. I use SSH
for a number of things:

1) As a secure FTP server
2) To tunnel through port forwarding to my Tivo to program it and download music
3) To stream music through the Slimserver music streaming software

I have been able to do all of this successfully running Bitvise's SSH
client called Tunnelier.  The client is running on a Windows 2000 PC. 
Furthermore, I have been able to do it even though I am accessing
through my company's proxy server or VPN - as long as I run SSH on an
open port.

Here's the problem:  when I try to use remote desktop, I am
experiencing problems.  In particular, when I open a remote desktop
connection (which is efftively done by forwarding port 3389 on the
remote PC to 127.0.0.1 or 127.0.0.2 on my local PC using a
client-to-server forwarding rule),  I get the Windows login screen,
and I am able to login and see my desktop. But about 5 seconds after I
login, I lose the connection with the remote desktop and the flashing
"lost connection" icon appears.   So the port  forwarding almost
works, it just seems to break right after I've logged in.

Here's the strange thing: when I  try to do the same thing when I'm on
an open network (e.g. in a hotel room) where I'm not going through a
proxy server, it works fine EVEN THOUGH I am still going through SSH
for the port forwarding. So, it seems to be the proxy server running
through SSH that is breaking things. What's even stranger is that
every other function of SSH seems to work fine - the FTP, the HTTP
port forwarding, etc.  The authors of SSH seem to think that it's
logically impossible for the behavior to be different through a proxy
server.

Note that I was able to get PC Anywhere working fine through SSH. 
Unfortunately, I  have found that remote desktop is superior in many
respects to PC Anywhere, so I'd prefer to use that if I could figure
out a way to.

But, I'm also curious why it's not working.

I have no idea how to turn on logging in remote desktop, but I could
supply a log if someone else knows how to do it.