zlacker

The problem is that each vote change the number of points, so if you happen to be the first down-voter, it will become zero. But if another user up-voted the same item just before you, then your vote change nothing.

I seems that reddit solved this problem by not showing the number of points for new messages.

There could be a "new" status, marked in a special way, which explain why you vote it not showing. After enough users voted, and using the editor vote to change the weight of other votes, move the item to voted status, and show its point count.