My new macbook pro i5 15inch (april 2010) is making a constant noise i haven't heard in my previous macbooks, including the last unibody from 2009. The noise is probably from the fan (though not the normal blowing fan noise from a macbook) and it kicks in from the moment i turn my macbook on... When lifting my mac and tilting it in different directions, i can clearly hear the rotational frequency changing, i can even tilt it gently in a particular position so the noise is canceled though only in said position which is not horizontal....very strange. (and it's not the hd acceleration lock that i'm hearing in action) Instead of further describing the noise, i attached a zip file containing an mp3 recorded directly with the internal microphone. You may want to play the file with quicktime/itunes (software volume open) on your own macbook speakers, with the physical keyboard buttons set the volume on the second bar and you shouldn't perceive much more than the normal noise levels of your macbook, now turn up the volume and you'll hear what i mean...after that, lower the volume till 0 and you should remain with your macbooks noise and compare if the sound is the same... Is it just me or is that sound not familiar to a normal functioning macbook?