Try to put yourself in the shoes of the interviewer. You got to interview lots of clueless people who call themselves programmers but are unable to do the simplest task. Once you spoke with enough people like that, the first thing you want to do is weed out the people who can't program, hence the FizzBuzz question.

Now, I am sure that you, skuhn are able to do those simple things, but the guy interviewing you doesn't know it. If he asks you a simple question that you can nail in 5 minutes, and answer "sorry dude, your question is so easy I find it offending", the interviewer will think you're an arrogant douche - that's how I would feel at least. Instead, just solve the problem he's asking you and move on.

If after that he keeps asking stupid questions, well, it's a different story and you probably wouldn't fit well in that company.