Package: x2goserver 
Version: 4.0.1.19-3.el6 
OS: Centos 6.7 

Package: x2goclient 
Version: 4.0.1.4-1.el6 
OS: Centos 6.7 

Architecture : 

- Dual screen 
- Gnome Desktop 
- Fullscreen 
- Xinerama enabled 

First connection : 

The first x2go connection is ok the full scrren is working as expected. (the only problem the first connection is that the keypad does not work). 
To fix keypad issue, I have to logoff and start a new x2go session. 

Second connection : 

After the second connection the xinerama does not work anymore. For example If I maximize an application, it is present on both screens. 
The worst is that the task bar is located in th middle of the screen. 

I I tried to logoff and reconnect again I have the same issue. 
To fix it I have to reboot the centos 6 (client side) and after the first connection is ok (but with the keypad bug). 

Troubleshooting : 

- Change task bar location 
- Change screen resolution 
- Disable sound and print 
- I also tried from last Ubuntu or fedora => same issue 
- I tried to change the video card (from nvidia to an intel) => same issue 


Any idea to fix this ? 
Thanks in advance.