I needed to upgrade gs to gs 9.15, so I ran setup yesterday. It wanted to update a whole bunch of stuff, including X. OK, fine, I hadn't updated cygwin in quite a while, and I had other stuff to do. 

After the upgrade, I can't display remote xterms. OK, my old X shortcut didn't work, but I found "XWin Server" and pinned it to my task bar. I launch that and I have the X server running, and a local xterm pops up. I ssh into my linux server, and run my xterm, and get "can't open display". I did these steps. 

- turned off my Windows Firewall (I am on a safe, local network). 
- launched XWin Server. 

In the xterm that popped up: 
dcw@dcwdt02 ~ 
$ xhost + 
access control disabled, clients can connect from any host 

dcw@dcwdt02 ~ 
$ ssh centos6 
Last login: Wed Dec 10 16:31:16 2014 from dcwdt02 
centos6% setenv DISPLAY 10.11.22.33:0.0    # I use tcsh 
centos6% xterm 
xterm Xt error: Can't open display: 10.11.22.33:0.0 
centos6% 

Is there something obvious? 

Note: when run xterm with the firewall off, the error is immediate. when I do it when the firewall is on, there is a delay before I get the error. 

This was all working on Monday with my older version of cygwin-x, which I think was a 2011 vintage. (I don't upgrade stuff very often for this very reason.) 

Attached is my log. 

Any help is appreciated. In general, I love cygwin and cygwin-x; it is awesome for a 25-year unix jock like me. 

don..