In http://meta.math.stackexchange.com/questions/1404/identifying-a-dis-accepted-answer/2936#2936 Hendrik mentions that the feature showing which answer was disaccepted is now available.
However the introduction of such feature caused a misrepresntation of reputation:
I had Wolfram|Alpha agree with me that the reputation is actually 212 and not 197 as shown in the picture. The reputation page here (which you may not have access to...) log is:
2 65706 (10)
1 65791 (15)
2 66013 (10)
2 65791 (10)
2 66013 (10)
2 65791 (10)
2 66013 (10)
2 66013 (10)
2 66080 (10)
2 66080 (10)
2 66080 (10)
1 66013 (15)
2 66013 (10)
2 66080 (10)
2 66080 (10)
2 40939 (10)
1 65616 (2)
2 66080 (10)
2 40939 (10)
2 66150 (10)
2 66150 (10)
-- 2011-09-20 rep +212 = 13625
The question from which the dis-accepted answer came from was posted on that same day, so it cannot be that I lost reputation that I gained at any earlier day by that action.