[linux-cifs-client] Mount over SSH tunnel

[cifs.20.DrLock at spamgourmet.com]

I am trying to pass a samba mount through an SSH tunnel to my file
server. The basic setup is:

Linux Client -- |Firewall| -- Windows File Server

The Windows File Server is running OpenSSH for Windows (BTW freeSSHd
has a tunneling bug and won't work) and can accept tunnels and local
forwarding.
I can create the tunnel, I can even browse the file server with
smbclient, but I can't get it to mount the samba share. My slightly
modified terminal session is:
  myuser at linuxclient:~$ ssh -N -f -L 20139:10.0.0.1:139 magni.domain.com
  myuser at magni.domain.com's password:
  myuser at linuxclient:~$ smbclient //magni/backups -p 20139 -U myuser
-I 127.0.0.1
  Password:
  Domain=[MAGNI] OS=[Windows 5.1] Server=[Windows 2000 LAN Manager]
  smb: \> ls
  . D 0 Fri Dec 22 11:16:38 2006
  .. D 0 Fri Dec 22 11:16:38 2006
  .Trash-myuser DH 0 Mon Feb 26 15:31:21 2007

  48618 blocks of size 4194304. 9347 blocks available
  smb: \> exit
  myuser at linuxclient:~$ sudo mount -t smbfs //magni/backups /mnt/bak/
-o port=20139,ip=127.0.0.1,username=myuser
  Password:
  mount error 112 = Host is down
  Refer to the mount.cifs(8) manual page (e.g.man mount.cifs)

10.0.0.1 is a loopback device on the Windows file server

Why can't CIFS talk to the host when smbclient can? This does not seem
to be a new problem. I have found many other people with the same
issue:
http://lists.samba.org/archive/linux-cifs-client/2006-November/001594.html
http://lists.samba.org/archive/linux-cifs-client/2004-September/000379.html

But I haven't found any solutions. Any ideas would be appreciated.

Thanks