I didn't noticed that on my iBook/PowerBook since they are equipped with mSata-SSD, but intalling an iBookG4 for a good friend, I 've noticed now, that using Safari/WebKit causes the HDD to work heavily - even on websites without animated pictures etc. Flash has been disabled by ClickToPlugin too. Anyone knows the reason for that? I've nearly unchecked all settings within the browser and extensions but there had been no effect on the "noise" coming from the HDD. As soon as I leave the browser the HDD stops working. This happed on two identical iBookG4 both with HDD and I also checked both the HDD.