Hi! Many thanks for your answer.
I was following this page:
http://scratching.psybermonkey.net/2...g-openssh.html

I tried with /etc/init.d/sh ssh restart
but no success.
Then, I tried as you suggested with /usr/sbin/sshd
but again no success.
I had installed SSH Status and Switcher to turn SSH on/off.

I don't know what's wrong.