Random digital items not showing download button after purchase

Hello All,

I have been using zen cart for 3 years now and within the last month an issue has arisen, I am not sure where to check the code.

I am currently using zen cart 1.3.8 - have lots of coding changes, and mods so I have not upgraded but have already done all the security suggestions

I have a linux server and its dedicated so no one else is doing things on the server.

hosting company is codero

my site is at http://www.bwscrapbooking.com/shop

the issue: I sell both digital and physical products. for about the last month an issue started occurring where random orders (1 in 10) where a customer orders digital items, the customer emails saying there is no option to download.

Each time I go to the attributes of the product in question and confirm the download location is green.

Then I purchase the same items an place an order. using a test account.

every time I am not able to reproduce the problem.

the current solution is I make a copy of their files and email the customers the url.

please help

thanks for your time

Jeff

Do any of the products in question have the attributes as optional, instead of required?
ie: such that the customer could accidentally add the product to their cart without choosing the download-file-attribute, and therefore it won't be presented to them as part of their order
Even if there's a green icon next to the file in the downloads manager, if the attribute can be "not" selected by the customer during add-to-cart, then they'll just simply not get the file offered to them.