On stackoverflow, I put +50 bounty on a question. Sure enough, a kind soul came and answered my question, so dutifully I clicked the check box for their answer and considered it done with. However, today I got a notification that my bounty was going to expire in 3 days - apparently you have to click the blue +50 icon to award bounty as well.
My suggestion: I had thought that accepting an answer awarded the bounty. I think that it would be better to make this actually the case, or at least surface a dialog box asking the user whether they also want to award the bounty for the question.