step 1: If you log in to osscommerce, go through to the confirmation page in the checkout process, an order will be created.
step 2: If you now log out (via the link), and log in as some one else, when you go through the confirmation page again in the checkout process, the same order_id will appear in the hidden form fields as from step 1.
To Fix this problem add this line to the logoff.php file where its unregistering the other session variables:
tep_session_unregister('cart_PayPal_IPN_ID'); // Fix Paypal IPN order_id miss-match bug
For the benefit of others looking for this issue...
- Wrong customer_id/custom in oscommerce paypal order
- Wrong invoice_id/invoice_number in oscommerce paypal order
it may also be related to the bug where the same invoice number is going through twice...