I have 2 stores that I upgraded from 1.37 to 1.39d.
One of the stores works fine, but the other one won't send a confirmation e-mail with the download link to the customer for books they buy. What's more, their purchases don't appear in the order list or in their customer history.
I've spent days going through IPN setting and trying to determine what the difference is.
Does anyone have a clue?

TIA, danbug