The counts on your summary page are almost always going to be off, because:
The votes tab counts up, down, deletion, undeletion, closure and reopen votes, your summary only counts up and down voting.
The votes tab can show you up or down votes only, but those counts are only for still-listed posts. Deleted posts are not counted in that view, so the counts will be lower than your summary overview where deleted posts are counted.
For example, my upvote count is 'off' by 28 on the votes tab, or 0.96% of the total, but my downvote count has a 86 vote discrepancy, meaning 46.24% of my downvotes contributed to posts being deleted.
So, not a bug, luckily. :-)