Don't use the front page - there's a newest question view that should do what you want
Questions tab on the left, 'newest' on top tab once you have, rather than the front page.
That said, both bumps of old posts (by the system), and updated answers to old questions is part of the model here - we don't just want to help the person asking a question but future people with similar issues, and there's value on necroposting.
Also, - a common pet pedantic peeve. this isn't a forum, its a Q&A site
