If you edit the thread title (edit the first post) and then post a new reply, the thread will be bumped and we'll see the new question.
Starting new threads for unrelated topics is fine, but I'd recommend making the thread titles more specific, with a reference to the question/problem rather than "Dude". It's similar to starting threads that just say "Help" (or more annoyingly, variations like "HEEEEEEELLLPPP!!!!!1!!!!"). Giving threads a title that's appropriate to what they're about usually tends to get a better response, since everyone immediately has an idea of what it's about.
