Issuers of Form 1099-R will often not mark the CORRECTED box if the change the form before the original is sent to the IRS and the original was never sent to the IRS. If that's what was done, the first one should be disregarded. In fact, a Form 1099-SA with $0 in box 1 is meaningless other than to say that there was no distribution, so it would be appropriate to disregard the original even if you hadn't received the second one.
