Here's something odd. Over the weekend I added a page designed around one mispell word its a two part word. It was ranked #9 by google on monday as of yesterday was still ranked #9. Then today I was checked its rank and its gone completely from Google, even using the domain in a search term. So I'm in Adsense and it also doesn't show up in my channels report. Its gone there too. I go into my Manage channels and its still there. It is against TOS to use a mispell keyword in file name, page title and page copy? The only other thing I can think is one image was next to the ad and gave me a high CTR.
That's weird that it disappeared from your channels report. Google will often quit indexing sites they don't like (for whatever reason), which means you disappear from the SE. I've never heard of anyone having a channel disappear along with that, though. Google usually only messes with adsense accounts when they decide you've been violating their TOS. It seems like, if that happens, they just cancel the account on a whim (assuming they don't turn around and sue you).
Why don't you take the adsense off the site and see what happens.....I'm prepared to bet that you will return...!!!
Although the entire site is fine its one page that was in question. I plan to sit on it for the week and see if it returns.