This question already has an answer here:
Today I notice that even if all the statistics works well and updates correctly for me and other, user stats in the top bar were all down to 'zero'.
A picture will describe better the problem than words :
This is not correct, as you can see in my profile page. Do you guys experiment the same or is it because stats have been initialized at the beginning of the month (and week). I've never noticed this before, however, maybe I've looked bad...