vwmike

I'm pulling my hair out here. I'm trying to set up google checkout on my site. I have oscommerce v2.2 RC2 and google checkout v1.5.0. I put in the merchant ID and key for both production and sanbox. It doesn't matter which it is set on, when you proceed to the checkout and hit submit it just takes you back to the cart where the items still are. What could be causing this? Thanks, -Mike