SCP Task - No response from server

Hi,

Up until now, I have been manually copying over my files that have been checked out of subversion by ANT on Windows, to an AIX server. I've decided to try to implement ANT so it does this copy for me. I have add the below lines of code:

  <scp todir="userName:pwd@IPAddress:/home/user">
        <fileset dir="filetoFTP"/>
    </scp>

But when i run my ANT script, i have the error message:
265: No response from server

I can ping this IP address and previously I had been using WinSCP to connect using the same IP address without any problems.

I am using ANT 1.6 and jsch-0.1.37.jar.

Am I missing something obvious here like a missing flag in my SCP task?