Twice since joining this site I have used up all my votes in a day. I thought this should have earned me the Vox Populi badge, but it has not. Is this a bug, or do I misunderstand the badge requirements?
All I can think is, are you sure you used up 40 votes in a day, or just all of your votes in a day? As nonsensical as it seems, the latter could be less than 40. Something about how they added 10 extra votes that you can only use on questions, not on answers, but I'll be damned if I can explain how it works. What ought to work is to make sure your first ten votes of the day are on questions. (Yes, downvotes count.)