Well, the problem with the flashing dates is that it isn't noticeable. Took me about 2 weeks to notice it when I joined AO, and it's because someone mentioned it to someone else. So the approach wouldn't be closing threads, sometimes thread creators want to add to it instead of making a new topic. My opinion, what should be done is something more noticeable, something that you CAN'T miss but you know that it means that you are trying to reply to an old thread.