Host key verification failed

I can establish a SSH session via a Putty client.
When I attempt to connect using SmartFTP, I recieve the following,

Connecting to Port: 22
SSH-2.0-2.1.0 dss F-SECURE SSH
Starting SSH session. Remote Id: "SSH-2.0-2.1.0 dss F-SECURE SSH"
SSH protocol version reply. Client Id: "SSH-2.0-SmartFTP"
Key Exchange Algorithm: diffie-hellman-group1-sha1
Host key verification failed.
Client closed the connection.

Any ideas on how to resolve the host key verification failure?

Thank you


Works, thank you.