Righto then - module installed and my Zen Cart seesm to be talking to the Worldpay server!
However this is not the result I was expecting. I assumed that the customer would enter card details into an https page on my site and that the details would be passed transparently to Worldpay - instead the customer is taken to the ugly ol' Worldpay pages to make the transaction. Is this the way its supposed to work?
Ta