I pulled my credit the day after my capital one statement printed. The balance that was reported as my capital one balance (+$900) was my balance at the end of last month. I paid my balance down to $100 (of a $2250 limit) before my statement cut. My credit score was 661.
I was under the impression that cap one reported when the statement cut so I just pulled my report again today - a week later - my balance is now showing as $100 and a score of 672. ( I don't usually pull this often. It's usually just once every 3 months or so)
So it looks like cap one reports to the bureaus twice - at the end of the month and a few days after your statement cuts.