Well that was unusual (my American Express bill)

[SackAttack]

Went to go pay my AmEx bill about five minutes ago, and it told me that I had a minimum payment of $0.00 due on the cycle that just closed.

In the past, I've only ever seen that happen when the already-made payment has exceeded the minimum. I've never seen that happen when a bill is as-yet unpaid (and I don't overpay bills, so there's no chance of last month's payment having had an extra $20 or something in it).

I know there's been talk about making legal changes to the way credit card companies do their reporting, but I hadn't heard about anything being finalized there. Is there something at work here I'm unaware of?