Never. :p Well I never click 'unanswered questions' on the Answer bar. I only answer questions I feel are interesting or that I can give advice on.:)
There's usually a reason they're not answered. Usually because they don't make sense (which I will not be bothered to decipher) or that they're too complicated that not many people can give insight on.
I do check it out fairly regularly. If they need an answer, I'll give them one. As long as it isn't one massive paragraph that the person didn't hit the "enter" button once in a while, I'll give 'em a chance.
I always go there first. They are usually the most interesting, If there is a dumb question, I'll usually answer it to get it off the list. Most importantly, the question is usually brand new and the person is online to read the answer.