i couldn't log in using JISQL

I'm tring to test the sample database provide by firebird
installation, and i install firebird in "G:\fireBird\Firebird_1_5\"

in JISQL i use the following:
username: sysdba
password: masterkey
host: localhost
port: 3050

and it gave me: java.sql.SQLException: JZ00L login faild
IOException: java.net.socketException: Connection
reset

Any one have any ideal?