name, number and quantity not returned in IPN

I'm using the basic "pay and receive IPN info" module (no donations, subscriptions or adverts) on a 4.7.4 site that lists a series of events for which people can register and pay on-line through Paypal. The module seems to be working fine except for one fairly significant issue. It makes the payment, sends a complete email with all info as confirmation to the payer and then retrieves and displays the IPN info except: item_number, item_name and quantity. Those fields don't display in the IPN report and are, in fact, blank in the database -- just show NULL.

The items are passed in a button on a cck type custom template with variables taken from the event node itself (in the listing). It's all customized but I think the variables are doing their job because all three pieces of info show up in the paypal cart and the confirmation email to the person who has paid. Just not in the db and the IPN report which is where I need them.

I KNOW I'm missing something. What could it be?

Any help would be a big help! :-)

Alfredo