I created a multi-page form which ends in a PayPal payment. On hitting "Submit" I receive an error message which says that my PayPal shopping cart is empty. The form has successfully been working for several months. It last worked correctly on Feb. 24 (yesterday).
1. Visit http://www.belax.org/2012registration/
2. Complete form until final page, "Payment," and then click Submit.
Note: Error message generated from PayPal, "Error Detected - Shopping Cart Empty."
I uninstalled/reinstalled the PayPal Add-On Plugin and reestablished the PayPal feed. It did not fix the problem. The form was working correctly for several months--then stopped suddenly.