Thank you for the tips. I have no idea how this works but for some reasons, I couldn't edit my paid out posts. However today, I was able to edit a post for the SteemitPhotoChallenge which I published hours ago. I don't know when posts get paid out but for some reasons - the other posts just popped me the same "comment.last_payout == fc::time_point_sec::min():DISMISS " message.