X2Go server NX proxy is refusing client connections

j:0 ~ $ x2goclient
Fontconfig warning: "/etc/fonts/conf.d/50-user.conf", line 9: reading configurations from ~/.fonts.conf is deprecated.
ONMainWindow constructor

ONMainWindows constructor finished, home Directory is: "/home/msx"

read  2  sessions from config file
start new ssh connection to server: "arrakis.local" : "4815" krb:  false

ssh connection ok

continue normal x2go session

"x2gostartagent 800x600 adsl 16m-jpeg-9 unix-kde-depth_24 us pc105/us 1 D awesome"

Agent output: "54
ccf4093f377129df8620e2433c3733b4
29798
arrakis-54-1357075674_stDawesome_dp24
30016
30017
30018
"
starting nxproxy with:  "nxproxy -S nx/nx,options=/home/msx/.x2go/S-arrakis-54-1357075674_stDawesome_dp24/options:54"

"
NXPROXY - Version 3.5.0

Copyright (C) 2001, 2010 NoMachine.
See http://www.nomachine.com/ for more information.

Info: Proxy running in client mode with pid '18254'.
Session: Starting session at 'Tue Jan  1 18:27:57 2013'.
Info: Connecting to remote host 'localhost:31016'.
Info: Connection to remote proxy 'localhost:31016' established.
"

"error en channel_write"  -  "Remote channel is closed"

"Error: The remote NX proxy closed the connection.
"

"Error: Failure negotiating the session in stage '7'.
Error: Wrong version or invalid session authentication cookie.
Session: Terminating session at 'Tue Jan  1 18:27:57 2013'.
Session: Session terminated at 'Tue Jan  1 18:27:57 2013'.
"

deleting proxy

nxproxy not running

proxy deleted

checking exit status
check command message

"error en channel_open_session" :  "Writing packet: error on socket (or connection closed): Operation now in progress"

close event
saving settings
done
waiting sshConnection to finish

sshConnection is closed