[mikestew]

I agree, carriers might be the likely candidate. As for a smoke test, I'm seeing reports from users on US carriers. If it were "phones break on some obscure carrier in China", okay, fine. But when it appears to be breaking on carriers that are available to the testing labs right there in Cupertino, meh, it's got to be at least one other thing.

As another commenter said, I'd love to see a post morteum strictly in the interests of "don't let this happen to you". Sadly, we're unlikely to ever see it.