Hi Jelani,
I am also having some issues with the "PayPal Payflow Pro" contibution by jasonabc dated: 17 Jan 2007 .
http://www.oscommerce.com/community/contri.../search,payflow
I have run the test cgi provided by the paypal SDK and everything works fine. But the PayFlow contribution by jasonabc returns an Invalid Credit Card error.
It appears that there are some hard coded or mis configured paths in the "includes/functions/php_pfpro.php" file to the executable, bin, lib and certs directory. I suspect we are getting the error because the response message from Verisign is NULL or something else besides Zero. Or maybe we are not even getting a response at all (also null) due to a lack of connection.
I am using a linux box, and currently troubleshooting this issue. I would appreciate it if you would let me know if you find a solution. I will do the same if I do not hear from you first.
I will try to capture the response message as it is done on the testcgi script provided by Paypal. This should help troubleshoot this isssue.
Best regards,
Sandro.