Please Please HELP : trouble running the Credit cart process

[navid]

Hi,
I installed Oscommerce on apache on FreeBSD linux
I just did orginal installation. I did not install any patch or contribution.

I use Authorize.net for Credit cart process.

I get an error says:
The following errors have occurred.
(13) The merchant login ID or password is invalid or the account is inactive.

I entered both of these info correctly. I create a transaction key and following is my setting.

Enable Authorize.net Module
True

Login Username
as it should be

Transaction Key
as it should be

Transaction Mode
Production

Transaction Method
Credit Card

Customer Notifications
True

Payment Zone
--none--

Set Order Status
default

Sort order of display.
0

--------------------

on other end in Authorize.net setting. The password requirement is Disabled.

Transaction Version: 3
and all following are blank
Receipt Page / Response/Receipt URLs Relay Response
Silent Post URL / Direct Response

Any idea what I am missing?
when I submit a purchase either I get above error or I get back to login page. Why checkout_success does not show?
Authorized.net also shows some to of the trascation logs, but all say General error.

i am sure I am missing something with shopping cart setting.

Please please please HELP !

Thank you
Navid