Xming clipboard only works one way

In X-Launch, “Clipboard – Primary Selection – Also map the PRIMARY selection to the Windows clipboard”, uncheck it.

You could try VcXsrv if you are using the public domain version of Xming (6.9.0.31).

https://sourceforge.net/projects/vcxsrv/

I've just discovered VcXsrv and in my quick test copy/paste works perfectly between Linux and Windows both ways. (Ubuntu 12.04 xterm, emacs and Windows XP)

Using the "public domain release" Release: 6.9.0.31 it turned out that turning on the -nodecoration option, allowed the clipboard from linux to be shared to windows

Using git-bash:

$ export PATH=$PATH:</path/to/Xming/>
$ Xming :0 -multiwindow -clipboard -nodecoration & 
$ ssh -Y <hostname> "gnome-terminal"

I could then highlight text inside the terminal window, and paste it around windows :)