Why does this occur?
There are a number of less critical items that are heavily cached server-side for performance sake (one of the reasons the site is as fast as it is).
Between today and yesterday, you answered 5 questions, so that appears to be the difference. If it doesn't update soon, to at least reflect your posts from yesterday, then I would suggest waiting a little longer. Eventually it will update, but because of the caching, if you want them to match, the only solution will be to take a couple of days off from answering ;-)