Just went to the Chase site to check the balance on my husband's Circuit City visa, with a mind to PIF-ing it before the statement cuts. And was rather surprised to notice that, despite the last payment having been due on (and paid before) October 3, there is now a payment due by October 28. I've checked back through every statement for the last 18+ months, and the payment due dates have always fallen between the 2nd and the 5th of the month. I know they move around, but to suddenly switch to the 28th seems rather extreme!
I've heard before that they like to do this sometimes, but... is there any reason for it, other than the possibility that they might just catch you out and be able to hit you with some lovely late fees? Not that it matters to us, as I'm far too obsessive a balance-checker for that one to get past me, but... still, I saw it and thought '!!!!!' 
@jmbfl wrote:
Never assume you know when the next payment is due. Read the statement or look it up on line. They may be decreasing the grace period for some reason. I don't think there is anything sinister going on. On the other hand I would call and question it. Then again, I question everything!
I never assume I 'know' when the payment's due (although granted, that is very good advice, as it's assuming like that that gets people in trouble!) - which is why there was no way we were going to end up falling foul of the rather drastic change in the grace period this time around... I see posts all the time (not on here, elsewhere, blogs etc) where people are claiming they were 'cheated' by the CCC because they didn't check their statement and have the payment set to go on a particular day of the month (BAD idea!), etc - and I have to admit to thinking, well duh, payment dates ALWAYS fluctuate, it's nobody's fault but your own if you don't check your own accounts to see when your own payments are due.... (which sounds a bit unsympathetic, I'll admit...)
... but still, I was kind of surprised to see that date suddenly swing forward a week, out of the blue. No matter, though - they'll get their money a bit earlier, and I'll amend my mental checklist of what cuts/reports when.
Maybe it's something WAMU-related, who knows... perhaps they're adjusting due dates to, erm, spread things more evenly throughout the month. Or something.