AV error while connecting to firebird with TIBConnection

[sonicer]

OS:FreeBSD6.3 release
FB2.0.3_1
lazarus 0.9.24
fpc2.2.0_1
I Can connect to the firebird database via isql tool,
with the same os login user,open the lazarus ide,and in then empty project,put a TIBConnection on the form,
databasename='/mydb/mydb.fb'
dialet=3
username='sysdba'
password='sysdba'
-- i changed the password of fb
hostname='localhost'
then when i change property "connected" of  the ibconnection1 from "false" to "True" , a dialog appear:Access vialation. then I click the "OK"button ,and changed the property again,then the who IDE hang up. And i have to kill the IDE.

with the similar setting on an WinXP OS, it works very  well .

I DONT KNOW Y. and i need help

Thanks a lot.