WorldPay Module Install

I have got the latest version of this module Worldpay 4.0 version 1.6.zip downloaded from
http://www.oscommerce.com/community/...earch,worldpay

But am having problems installing it on osc_ms2_max_1_5_5 version.

The files uploaded are all new files and do not change any files on ms max. the only change is a line added to

Add: define('FILENAME_WPCALLBACK', 'wpcallback.php');
To catalog/includes/filenames.php

I'm not sure if this should also be added to
catalog/admin/includes/filenames.php
i did add the line there too!

but in the admin login area I can not see the file to activate it
I have look in the Administrator File Access
there is no reference to worldpay
I clicked the green button and look in the dropdown box,

I dont have an account with worldpay yet but this should not stop the module from appearing in MS MAX. What am I doing wrong?

It is in modules/Payment Modules, its named Secure Credit Card Payment, I was looking for a module called worldpay.