I believe that I have followed the instructions accurately. However, after a successful transaction, my users are not being redirected to the success= page. They stay on the transaction form and a message shows up indicating that they should log in.
This only happens for new users who are not logged in and are creating an account at the time of purchase. Existing users who are logged in get redirected to the correct page.
Here is my shortcode:
[s2Member-Pro-PayPal-Form level="1" ccaps="ccaps" desc="GRC Professional (GRCP) Exam" ps="paypal" cc="USD" ns="1" custom="www.grccertify.org" ta="250" tp="12" tt="M" ra="250" rp="1" rt="Y" rr="1" accept="paypal,visa,mastercard,amex,discover,maestro,solo" accept_via_paypal="paypal" coupon="" accept_coupons="1" success="http://www.grccertify.org/next-steps/" /]