I bought a refurbished D40 about two months ago so its still under the 90 day warranty. Anyway, I noticed that when there is low light the autofocus starts struggling and starts oscillating back and forth and has a hard time locking onto the subject. When I say low light I don't mean night time, I mean indoors during the day, etc. I just don't remember it doing this too much or at all until now. I know the D40's meter has tendency to overexpose a bit, does it have anything to with the meter. Should I be worried? Any suggestions besides sending it in? Another thing is that I noticed a small fuzzy dark spot is now appearing in my photos. The lens has never really been removed but I still am assuming it is dust or some small particle somewhere inside, any suggestions? I'm just wondering if I should just pull the trigger and send it in, and whether or not they are actually going to find something wrong with it or not, thanks!