On Area 51, my site reputation is reported to be 898, while from my drupal.SE account page I get it is 1077. The difference between 1077 and 1178 (my actual reputation) is the 101 bonus points I get because I associated two different accounts.
Why is there any difference between my site reputation, and my actual reputation?
I suspect the difference is caused by the data being cached from Area 51 in different ways; for other users I see there is a difference between the site reputation and the reputation showed close to the gravatar, but the difference is normally 10 points (and not 280).
Update: The difference between the two reputations is less evident, and probably doesn't exist anymore; I cannot know for sure, as my site reputation is now reported to the 1K.
Still, it could be interesting to know why there is such difference for two values that should be equal.