Apple randomly canceling some iPhone pre-orders? Update: AT&T pre-orders too?

We haven't verified exactly what's going on here, but we've gotten several tips tonight from people who've received an iPhone 4 pre-order cancellation email from Apple saying that their order couldn't be authorized. That sounds like an AT&T authorization problem to us, and given the litany of problems that Apple and AT&T had all week dealing with the huge number of pre-orders, we can't say we're too surprised to hear that the chaos continues. Here's the email:
Dear Customer,

We were unable to complete the authorization process for your iPhone order. As a result, we had to cancel your iPhone order. To complete the purchase of your iPhone, please visit an Apple Retail Store or an AT&T company-owned retail store.

We apologize for this inconvenience.

Apple Online Store Team
Uh, yeah. We're obviously looking into the situation, and we'll let you know what we find out.

Update: We're hearing that some people are getting cancellations from AT&T, as well -- curiouser and curiouser.

[Thanks to everyone who sent this in]