Due mostly to my two answers to the popular question Are there any open mathematical puzzles?, I received $35$ upvotes today (in the sense of UTC time). As a user can only receive reputation for $20$ upvotes in one day, I received $200$ reputation from this activity. A couple of minutes ago I received a downvote (annoyingly, with no comment left) for my answer to the question Subgroups of $D_4$, and there was a deduction of $2$ reputation. So in a day with $35$ upvotes and one downvote, I had earned $198$ reputation. If I had received the downvote first and then the $35$ upvotes, I would have earned $200$ reputation (I know this because since writing, I received another upvote which gave we $2$ reputation).
Should the order of the votes effect the total reputation? Is this the way the system has to be in order for a user to be penalised when a post of theirs is downvoted?