[paramiko] paramiko ssh client. connection from *nix --> win problem

[wDevil wDevil]

On win server installed freeSShdserver(http://www.freesshd.com/).
Connection to win:
#!/usr/bin/python
import paramiko
import sys
client = paramiko.SSHClient()
client.set_missing_host_key_policy(
    paramiko.AutoAddPolicy())
client.connect('host',22, 'client', 'client')
res = client.exec_command("dir")
print res[1].read()
sys.exit()

$ ~/py.py
Unable to execute command or shell on remote system: Failed to Execute process.

in shell works fine:
$ ssh client at host
C:\WINDOWS\system32>

------------------------------------
paramiko version:
$ dpkg -l | grep paramiko
ii  python-paramiko                            1.7.4-0.1
                         Make ssh v2 connections with python

freeSSHd version:
freeSSHd.exe	  1.2.6