I've also lost (since late this afternoon) the all-day every-day targeted ad in the number #1 position on all my pages that's been targeting the site for about a year now, which I would call quite a coincidence.
Well they haven't announced it in this forum yet, but AdWords is having "down for maintenance" Saturday on the 13th, and I'm sure AdSense will be down too. Maybe they'll kick the servers, shake loose some o' them bits.
I subscribed to a live Adsense tracking service (Adsense Detective) and found that my Google reports are consistently 2-3 hours behind. I can't be 100% sure though since the service tracks all clicks on Google ads, even Link clicks which don't always generate a paying click. I will post again if Google starts to catch up.