The Nike + interface has its flaws. One of them is that you can not set an exact time for a challenge to start. Another is that if one starts a challenge the same day another is finished, and the winner participates in the new challenge, his or her kms are counted twice. Not fair. So I tried to set the new challenge start for Nov 26 to leave everyone a day to rest. Now, for some reason, Nike+ changed it to Nov 25. Why, I have no idea. And it might be that your kms from morning of the 25th don't count, because it wasn't yet the 25th wherever Nike is (Oregon). I'm afraid this might be the case.
I'll mail Nike+ to see if they can reset the challenge start to reflect our time zone.