Although there are a lot of questions here about problems displaying up/down vote totals, I wasn't able to find one quite like this. Here are the steps to reproduce:
Visit this question:
Click the '8' to display vote totals:
Upvote the question:
Wait! 81? Where did that come from?
Now reload the page and click the '9' to display vote totals again.
Remove your upvote:
I haven't tried reproducing this on any other Stack Exchange sites.