As Timothy wrote in his last post the issue why SQL Server is frizzing without doing anything is that the fingerprint of the Unix server was not cached in the registry for the user for whom SQL Server is running.

To omit this problem one thing need to be done:

Add to registry for user for whom SQL Server is running (or SQL Server Agent if you wont to use PSCP in SQL JOB)

KEY in a directory:

\Software\SimonTatham\PuTTY\SshHostKeysand looking like this:

name: rsa2@22:xxx.xxx.xxx

xxx.xxx.xxx - IP address of a Unix server from/where you wont to send a files

type: String

value: fingerprint of Unix server (if don't know from where you could take such fingerprint, you should start PUTTY and try to login to the Unix server. (of course if didn't make it before)). During logging attempt a fingerprint of a server is being added to a registry. Now you should look to registry and find in a directory HKEY_CURRENT_USER\Software\SimonTatham\PuTTY\SshHostKeys\ key that name look like this rsa2@22:xxx.xxx.xxx.

Value of this key need to be copied to the key created by you for SQL server user.

I have hope that it will help if you will have similar problem.