Hi,

>We have a guardian program of our own that fires up our message
>server that talks to the database. When the gateway fires up, the
>error is
>
>335544472, your username or password are not defined. ask your
>database admin to setup a firebird login.
>
>
>

You should backup and restore old security database as well. That is
were firebird keeps information for users.
The old name (version 1) is isc4.gdb, now (version 1.5) it's called
security.fdb.
Backup it in your old server, and restore it with this new name. Use
sysdba/masterkey as username password to restore.
Restore to a different place, stop the server, copy the file to Firebird
location, restart the server.

Artur