I followed them as best I could. As I said, the wiki is not accurate and creates confusion. However, the integration guide (PDF) gave an example of a static HTML page for the Confirmation page - that ...
I changed the "Thank You" page from a static HTML page to the cart CGI page, despite the support tech's assurance that this shouldn't matter at all. Our test order went through fine and was ...
That's exactly what I followed. I've also spoken to YourPay support and they say everything is configured correctly (though I'm a bit dubious as they didn't sound like they really knew what was going ...