I decided to make a new post since I don't know if you with fan problems have this exact one. My fan is off when I start my DNS-323 and it remains off up to at least 41C when I use it (watched movies for maybe 3hrs yesterday and it never started), but when it goes into idle mode the fan starts and then it never stops.
I have 1.09b1 right now, I have factory reset it, re-configured it several times and nothing works.