Adam Maloney wrote:
> You might try running:
> 
> xhost +remote.hostname
> 
> on the box you're trying to display on (the one with X).

Thanks Adam, here's the output when running that command:

Xlib: connection to "localhost:10.0" refused by server
Xlib: PuTTY X11 proxy: wrong authentication protocol attempted
xhost:  unable to open display "localhost:10.0"