From my reputation development yesterday, I believe there is an inconsistency between how the site treats downvote reputation loss, and how it's treated in /reputation.
Because of migrated and deleted questions, there will probably always be some difference, but in this case, one of the reputation calculators is simply broken.
Hypothesis
When downvoting an answer, the site removes 1 reputation, and reduces the daily reputation cap by 1. One downvote means that reputation from upvotes only is capped at 199.
The /reputation page removes 1 reputation, but the daily cap is not reduced. More than 20 answer upvotes will still gain a user 200 reputation.
Data
This is yesterday's reputation report:
2 384380 (10)
1 384689 (15)
2 384689 (10)
3 384528 (-1)
2 384713 (5)
2 384713 (5)
2 384713 (5)
1 384735 (2)
1 373133 (15)
2 384770 (10)
2 384770 (10)
2 384770 (10)
2 384770 (10)
1 384770 (15)
2 384770 (10)
2 384770 (10)
2 384770 (10)
2 384770 (10) *
2 384873 (10)
2 384880 (10)
2 384880 (10)
1 384859 (15)
2 384859 (10)
2 384880 (10)
2 384770 (10)
2 384873 (10)
2 384859 (10)
2 384770 [6]
-- 2012-02-01 rep +262 = 30079
Around the time of the * marked line (+/–1), I manually triggered a reputation recalc that reduced my reputation from 30,003 to 29,978.
At the end of the UTC day, I had 30,078 reputation.
The very last upvote was only worth 5 points, from 30,073 to 30,078 on the site.
The /reputation data says it's worth 6. All votes are the same as listed in the reputation tab of my user profile.
This unnecessary discrepancy is the bug.
