The vast majority of PayPal audit rows refer to donations we've already recorded via the IPN listener. We currently validate audit file rows before we check for the donations in the database. This means that we squawk whenever PayPal makes an omission, even if that omission doesn't affect our own data integrity. We've been complaining about the missing subscr_ids for years now and they haven't fixed it, so maybe we should lower our expectations and reduce the noise in our inboxes.