I think that something strange happened to my reputation. Yesterday, I answered a question for which I got two upvotes, but only ten points were added to my reputation. The first thing that I did was to go to my reputation history and there I found this:
But when I go to the question, I see that I have two upvotes, without downvotes:
What happened in this case?
You don't have an down-vote. You have an "unupvote".
Three people gave you an upvote (3 * +10), but one of them took it back (1 * -10). Only two of those upvotes were today, but the unupvote was also today. So your net reputation for the day is 10, while the score on the answer is +2/0.
However, a closer look at your reputation history seems to contradict that. It could well be that there's caching going on on your reputation page and it all sort itself out by tomorrow. I wouldn't worry about it too much. The score on the post is really +2/0 - clicking the score to see the vote split fetches the vote and refreshes the page to show the correct values. The reputation page updates are delayed when the are down-votes involved to make it hard for people to work out who down-voted what, though that's usually only by a few minutes - not 13 hours.
