DSM-G600, DNS-3xx and NSA-220 Hack Forum

I have been using SSH keys from my computer to log into a remote server and the DNS-321.  However, when using the same setup (with key password), I am unable to SSH from DNS-321 to remote server - I get asked for my DNS-321 key's password every time.  Using a key without password works, but as far as *every* tutorial on this forum and on the net mentions, it's NOT a good thing to have a password-less key.  I have attempted this both as root and a standard user on the DNS.

Using a passworded key, here's a summary of SSH attempts:

1) computer TO remote server: works
2) computer TO DNS-321: works
3) DNS-321 TO remote server: asks for key password

The .ssh directory permissions are 0700, the authorized_keys and (remote server) has been set at 0600 and also tested with 0644, the public key is 0644, the private key is 0600. Using:  ffp 0.5 on DNS-321 FW v 1.03 (latest) with Mac OSX 10.5.8.

My goal is to nightly cron an rsync from DNS to remote server and download files, backups, etc.  I can cron, I can rsync, I just can't rsync/ssh with a passworded key. :-(

What am I stupidly missing on the DNS's standard ssh setup?