In stackoverflow if we go to users tab the reputation is different than when we go the users profile.
It looks that the profile shows the correct reputation.
You're probably looking at the reputation accumulated this week:
The page used to show all reputation by default, but it was a bit boring always seeing the same people, so when the page was redesigned the tabs were added to show reputation accrued over different spans of time. Click the "all" link to show total reputation