We just went live with our subscription site on 10/10/07, www.SacredFireMagazine.com

1.3.6 + SecurePay.php

We neglected to test Mastercard previously, but all card types are enabled in the payment module and on the SecurePay side (which I'll have to re-verify)-- the "Step 2" of checkout returns this for my customer and my Mastercard (live mode):

"The Credit Card Number does not match the Credit Card Type"

The card I tested begins with 5291 (16 digits).

Has anyone seen this? Unfortunately the SecurePay module does not (yet) do database capture and logging.