If you run SSH on HP-UX
I wonder why you didn't install the HPs' own port of OpenSSH that is neatly bundled into an easy to install and run SD depot,
and freely available for download in a pretty recent release
Hewlett-Packard Co.
If the provided URL isn't reachable go to
Hewlett-Packard Co.
and search for secure shell.

As you mention that the client gets locked out after 3 failed authorize attempts,
have you converted your HP-UX box to trusted system?
You can recognize if the following directory exists, /tcb/files/auth/

Also, how is your sshd configured?
Have you set MaxAuthTries in your sshd_config?