When I try to vim /etc/profile or vim /etc/motd it stops.
When I try to
touch those files it stops.
Any ideas? Nothing in the ssh logs that seems to be pertinent.
There was a similar message on the Cygwin mailing list on July 31, 2012. The solution quoted there is:
So how about trying out this advice?
And seeing that you are quite active in SO, you may be interested in what seems to be the actual fix to your problem.