Hi all,
just to say that I found the solution to the problem; I've added this line:
ServerAliveInterval 5
in:
/etc/ssh/ssh_config
The company providing me internet access told me that the problem was due to the limited number of 'real' ipnumbers they have so from time to time I was losing my ipnumber and then getting a new one. They suggested to use public ip number, but it is expensive.
I found that that extra line fixes the problem...
Ciao,
Marco