PayPal button goes right to success page and gives free subscription

We just went live with my clients web site. On the test servers everything worked great going to the sandbox and the live site.

We moved the site over the the live hosting account, which changed the domain from the test servers to the live server.

And now when somebody goes through a membership and goes to pay, when the click on the PayPal button, instead of going to PayPal it goes right to Welcome, Thank you for subscribing. We hope you enjoy the content page.

This happens when the payment gateway is set to test site and live site.

Any thoughts would be appreciated.