ichat services 10.6 server

Server software updated, and server restarted. ichat service is unavailable to clients...

When an individual client opens ichat, they are marked as OFFLINE. When they attempt to change their status to AVAILABLE, a new screen appears in which they are advised that they can't log into the Server because LOGIN ID or PASSWORD is incorrect...

Within this screen, A LOGIN ID BOX is already populated (accurately) and when they enter their usual Mac password, they enter a loop of this screen returning to the foreground each time they enter their password...

Keychain Access indicates/confirms that they ARE using the correct username and password...

any solution, please