sshd won’t start – cipher_encrypt bad plaintext

On a machine running 10.3.9, I can't get sshd to start. The error message: cipher_encrypt: bad plaintext length 461 Previously I had been able to ssh to this machine. Then one day it stopped. When I rebooted the machine to attach a monitor, I ran fsck as a precaution. There was the following error: Overlapped extent allocation. The file was ssh_host_key. I deleted and then tried to recreate it with the following command: ssh-keygen -t rsa1 -f /etc/ssh_host_key -N"" Can anyone tell me what the error means and how to fix it? Thanks