I've found that on questions with many answers the highest voted answers are usually those that were posted first.
When I'm short on time and I go to a page with a relatively new question, I'll read the question and then the first answer. If its a good answer, I'll upvote it. If the next several answers have significantly fewer votes than the first, I assume they must be of lower quality and don't bother to read or upvote them. The first answer (or two) thus continues repeatedly to get more upvotes even though it may just be getting more upvotes because it's newer. Other high quality but newer answers are skipped because the vote totals imply them to be of lower quality. I assume that many other users of this site probably follow the same behavioral pattern as me when reading and voting.
To help ensure that the best answers get voted to the top, rather than just the answers that appear within the first few hours, I would like to propose a feature request:
For the first 48 hours after a question is posted, the number of votes on answers should not be shown. (Instead a message explaining that the vote totals will become visible in n hours should appear instead.) Vote totals for your own answers and for answers to your questions would always be visible to you without having to wait for the 48 hours to pass.
As is currently the case with answers with equal numbers of votes, all the answers would be displayed in random order. This randomized ordering of the answers when people visit the page throughout the first two days should help to ensure a more even distribution of voting. After those first two days, the vote totals should be shown, thus giving future visitors an actual record of what the "best" answers to the question are.