> Unknown Database
> Unable to complete network request to host "localhost".
> Failed to establish a connection.
> Unknown Win32 error 10061
>

That is a winsock error message, a quick google.

WSAECONNREFUSED (10061)

Connection refused. No connection could be made because the target
machine actively refused it. This usually results from trying to
connect to a service that is inactive on the foreign host.

(ie, for whatever reason, the Firebird service stopped or a firewall
makes it look that way).

Adam