Looks like Google is having problems with Adsense reporting.
Last Month: [theregister.co.uk...]
For this one, Google "finalized earnings AdSense October" and you'll see it's all over the web. I'd expect it's a payment & reporting bug too.
I suggest everyone download the details of their October earnings from the Adsense reporting console, (click "Overview, last month", then click "Export to Excel CSV"). That will show the correct amounts even if the Estimated v. Actual of the Dec. 1 payment amount is not correct.
BE SURE TO SAVE THAT FILE! It will be your only evidence if they do short you.
If they don't fix within 24-48 hours, we need a concentrated effort to get them to fix ASAP or payment for Dec. 1 may be VERY short, and they may not catch up payments til January.