Help! Error message during checkout!

[KTNaturals]

I have a free item set up in my shop (a free sample kit). When a customer orders only that item and selects PPEC at the checkout page, after you go through the PP screen and hit the "pay now" button, I get bounced back to checkout_shipping page with an error at the top that reads

10413 Transaction refused because of an invalid argument. See additional error messages for details. - The totals of the cart item amounts do not match order amounts.

The product is marked free with the original price of $8. Normal shipping rule applies because I want customers to pay shipping.

I get an alert email with the same error message.

http://www.ktnaturals.com

Thanks!
Katie

[KTNaturals]

Changing the item to $0 instead of "free" did not fix the problem. For now, I set the price of the item to $0.01 so customers can at least place an order. I've already advertised about the free sample kit, so I'd appreciate it if this gets looked into.

[kobra]

Have you applied the patch from here http://www.zen-cart.com/forum/showthread.php?t=56216 ??

[ryhn]

Did you uninstall the ot_subtotal module? That will cause 10413 problem in my experience.

[KTNaturals]

The lastest patch was applied when it came out, and I removed and reinstalled the payment and order total modules. This happens on a fresh 1.3.7 install also.

So this only happens with products that are $0, marked free or not. This does not happen with IPN - just Express Checkout.

[kobra]

I was hoping that DrByte might chime in here as he knows this module coding the best...but will look at this glitch and post back

[DrByte]

Changing the item to $0 instead of "free" did not fix the problem. For now, I set the price of the item to $0.01 so customers can at least place an order. I've already advertised about the free sample kit, so I'd appreciate it if this gets looked into.

Your workaround is the only option at this time.
If you're charging for shipping, you'll need to charge at least a penny in order to force the system to not treat the order as free, but to instead collect shipping information from the customer before checkout.