Here is the error message, it's just a generic "catch-all" 500 error.

"HTTP Error 500 (Internal Server Error): An unexpected condition was encountered while the server was attempting to fulfill the request."

I will contact my host to get more details on the error.

The Fast and Easy Checkout module that I'm referring to is this: https://www.numinix.com/fast-and-eas...cd4714de3a168d

And finally, here is a copy of the order.php modified core with the maxmind code merged in. As you can see, I've tried both lines of code where it submits 6 vs 4 digits to maxmind (by commenting one of them out) and either way results in the internal 500 error. http://www.robophung.net/zencart/order.php.bak

And you can also see, that the order.php is drastically different than the original order.php for zc 1.3.9h... but I think I merged your code into the appropriate spots.

Thanks for responding, and I hope u can steer me in the right direction...