Hey all, I ust got a macbook a few days ago, and it was perfect, dead quiet it was spectacular. Anyway I had some problems with kernel panics relating to the headphone jack. It would crash if i removed headphones in some instances, very strange. So I downloaded the march security update for osx, and since I have that on I have mooing (the constant fans powering up and powering down). Its actually really irritating because I know that I didnt have it before at all. But, I havent encountered the headphone problem again yet... so perhaps it has fixed that, but started the mooing. Anyone had a similar experience ? Anyone have a suggestiong of what my course of action should be, should I get a replacement?