ssh generation does not work

Hi guys,

- I'm trying to make a configuration that i've done too many time. I wan't
a script to execute a command in a remote server without the need to type or
pass the password.
- I'm using the follow commands:

scp .ssh/id_rsa <remote_user>@<remote_machine>:~/
ssh <remote_user>@<remote_machine> "cat ~/.id_rsa >> ~/.ssh/authorized_keys"
# Here i still neeed to use my password but thats right.
ssh <remote_user>@<remote_machine>
# Here i still neeed to use my password and that's not good because
i already typed the command to add the public key from my local user in the
remote machine.

- Does someone has any idea of what i'm doing wrong? I did it may time
before and always worked. Does someone know if i have to make some
modification at the /etc/ssh/ssd_config of my local machine or the
/etc/ssh/sshd_config of my remote machine for this to work?
- My local machine is a "FreeBSD 7.0-RELEASE-p1 generic amd64" and the ssh
is "OpenSSH_4.5p1 FreeBSD-20061110, OpenSSL 0.9.8e 23 Feb 2007".
- The remote machine is a "Red Hat Enterprise Linux ES release 4 (Nahant
Update 5)" and the ssh version is "OpenSSH_3.9p1, OpenSSL 0.9.7a Feb 19 2003

Helio Campos Mello de Andrade