I have asked this question more than one year ago, Encoded character buffer storage problem in MySQL varchar using C. After two or three days I got the answer, so I accepted the specific answer, and got 2 reputation points for accepting the answer. But yesterday I unmarked the answer and then remarked it. I got 2 more reputation points. Why did I get 2 more reputation points?
The original accept was cancelled and the 2 reputation was removed from your account. However, you cast another accept, which earned you +2. In other words,
+2 -2 +2 = 2, so everything comes out right in the end.
If you search through your accept list, you'll notice it only shows up for yesterday—the old accept is gone.