not logged in - 500 error coming back for confirmation on order

[Tuner]

using Zen Cart 1.50 with Apparel_Boutique template

if my customers are logged in then the PayPal Express Checkout works perfect

however if they are not logged in and go directly to PayPal express checkout when they are taken to the PayPal screen and login to their PayPal account, everything comes up with their PayPal info but when you "Continue" the PayPal does not come back to the cart. There is an error for the page coming back to my cart in the ipn_main_handler.php file passing back and from the log it appears to be because they are not logged in to Zen Cart.

Again if they are logged in it works.

Thank you in advance for any help!!!

[RodG]

There is an error for the page coming back to my cart in the ipn_main_handler.php file passing back and from the log it appears to be because they are not logged in to Zen Cart.!

1. Can you duplicate the problem.
2. Can you provide us with the relevant part(s) of the error log. It may mean more to us than it does to you.

Cheers
Rod