LinuxQuestions.org - Fedora 14 on Amazon EC2 EBS -- sshd problem

Hi,

I've got Fedora 14 running on an EBS volume on Amazon EC2.
I've created a few users and enabled port 22.
When I set a password for these users, they can successfully ssh into the instance; even if they logout and login again....until:
If I reboot the machine, they can no longer ssh into the machine (permission denied).
If I issue the passwd <user> command and change their passwords, they can login again....until I reboot the machine at which time they cannot login again until I change their passwords.
The problem exists even from the machine. That is, if root attempts to ssh into 127.0.0.1 using their username/password, the same problem/resolution exists.

Of course, I'm probably missing something.

Any suggestions?

Thanks!