[Done 1.3.9] Wrong payment method asigned to orders when gift certificate is used

The only way I can get the payment method to be listed as "Gift Certificate/Coupon" in emails and and on the orders page is to disable all payment modules, all but the FREE CHARGE CARD one that is. I am paying the entire total with the gift certificate and it will list whatever payment module I enable as the payment method. I am using version 1.3.8a. I looked around but I couldn't find a reference to this anywhere.

Thanks,
Jim

More info....
At first I wasn't able to reproduce this error on a fresh install and I thought I was going nuts, well I am nuts but I shouldn't bother any of you with this.

This only happens when only one payment method is being offered. Any work around for this would be greatly appreciated.

Jim

Well I'm no programmer but my best guess is that where sets a default payment method if only one method is offered something needs to be added to account for zero balance due when paid by gift certificate. It looks like this default is set around line 77 of /includes/classes/payment.php
Commenting out this line of code around line 84 seems to fix this but I have no idea what else this might effect?

if (!$credit_covers) $_SESSION['payment'] = $include_modules[0]['class'];

I hope this is helpful.