I cannot see any downvotes but my reputation was decreased by 8 points on UI site: from 752 to 744. The same situation on http://dba.stackexchange.com site: from 852 to 848 (4 points). At the same time my stackoverflow.com account got additional 14 points. What is going on?
Reputation score is denormalized, so it is expected for it to vary slightly from the "real" value over time. We periodically recalculate everyone's reputation to bring it in sync, roughly once per year.
Some ways reputation can be affected without being updated live:
You can always check
to see the live calculation of your reputation, and optionally recalculate it to reflect the current, most correct, value.