ssh is refusing connections

[Aaron Brashears <gila@gila.org>]

I've been running my server for 89 days now, on potato for the whole
time. It's been quite stable and happy for a while now. However,
without an update to either the server or my portable machine, ssh
began refusing connections all of a sudden. 'Garrison' is the
machine's local name, as listed in my /etc/hosts. Here's what's
happening:

$ ssh garrison
secure connection to garrison refused
$

Earlier in the day, this worked fine. I then ssh'd over to a friend's
server, and can ssh from there to my server.

Any help or ideas?