One of our sites who uses the PayPal module got this error and was using the similar URL.
I looked at my copy of Zen Cart and the PayPal module was saying this in it's config:
Is this correct? Will it fix it if I change this?NOTE: On www.paypal.com,
set your PayPal IPN Return URL to:
http://www.domain.com/catalog/index....eckout_process





