515911 Moneris Setup Fix

Have you done any Moneris gateways for ecommerce websites? Specifically, I'm looking for a fix to a website that's using CubeCart. Are you familiar with CubeCart? The site posts the data correctly to Moneris. Then the transaction takes place on the hosted payment solution of Moneris. When the customer presses the button 'process transaction', the website does not redirect correctly back to the website. It throws a 401 error. The budget is $75 for this fix. Please let me know if you are interested.