Comment 5 for bug 716310

Oops, I also meant to ask you to cat the /var/run/sshd.pid to make sure it is in fact the same as the one in status.

My suspicion is/was that the upstart managed sshd is conflicting with a /etc/init.d/ssh managed sshd. On second thought I'm not so sure.

Can you try running an sshd in debug mode on an alternate port on the server?

/usr/sbin/sshd -dd -p 2222

Then connect to it with

ssh -p 2222 affected_host

and paste the output of those, noting when the disconnection happens?