Have a problem with the variable name "MODULE_PAYMENT_PAYPAL_PURCHASE_DECRIPTION_TITLE" appearing on your PayPal payment pages instead of what it's supposed to say?

This is an indication of a missing variable in the zen cart <?php?> and nothing to do with Paypal.

Insidious

I got it zenned. There is a typo in

../includes/modules/payment/paypal.php

Line #234 : 'item_name' => MODULE_PAYMENT_PAYPAL_PURCHASE_DECRIPTION_TITLE, is mis spelled.

Just make the correction MODULE_PAYMENT_PAYPAL_PURCHASE_DESCRIPTION_TITLE

now it will match the variable name that is defined in

../includes/languages/english/modules/payment/paypal.php

Line #54 : define('MODULE_PAYMENT_PAYPAL_PURCHASE_DESCRIPTION_TITLE', STORE_NAME . ' Purchase');

ta daaaaaa