I'm trying to connect multiple Putty Sessions at once, and have a single CygwinX server running on my machine. The first putty session i open is able to successfully launch a gnome-terminal, proving that the X11 forwarding is working. However, the problem is any subsequent Putty sessions I launch to other machines while this first one is still open, won't successfully launch a gnome-terminal.
I assume that you are connecting to the remote host via SSH, and that you have X11 forwarding activated.
In a Cygwin terminal you would then type
After that you should be able to launch additional X11 applications that will display on your local X11 server.