It just sounds like you may have a key problem
Step 1
install stup ssh and make sure it is running you can use putty or telnet to test
telnet to port 22 on remote system
Step 2
generate a key on local system ( as user required )
ssh-keygen -t rsa
Follow the on-screen instructions, but don't set a password when prompted, as you will then need to enter the password each time you want to use the key. This creates a private and a public key file.
Step 3
Now you just need to
append the contents of the public key file in
.ssh/id_rsa.pub, and append it to the
.ssh/authorized_keys file on the remote host and user you want to use when logging in. You need to append the public key file contents to each machine you want to log in to automatically.
Note
if you want to go back to the other system make sure you create a key on each system and then just need to
append the contents of the public key file in
.ssh/id_rsa.pub, and append it to the
.ssh/authorized_keys file
OpenSSH is now bundled with AIX