I also so that happen to my stats once, for a month or more back they were all way wrong suddenly, then in a few hours or I think it was before the next morning, mine were all set back but were slightly all less then before lol
I dunno if this is really a bug, but my Payment History does not equal my Report table from when I started, til the end of June. It's weird.
Unfortunately I saw the total before I saw the doubles, and almost fell down - I though I'd hit the big time in traffic this week.
let me tell ya! adsense stats will drive you crazy! They are always lagging way behind, and you never know what to believe! hehehe I run asrep which tracks impressions and clicks, and that data never matches googles data! Who knows!!
Sometimes that will happen if you have two channels that cover the same situation. Check your aggregate report.