Hiya Folks. So recently I decided to do a harddrive upgrade on my Unibody Macbook Pro (MB470LL/A) Purchased the Seagate Momentus ST9500420AS 500g 7200rpm. Didnt get the g force protection, as I had read some conflicts with the inbuilt sudden motion sensor. Installed beautifully and machine seems to be running smoothly and quicker in comparison to my older hard drive. However (this is where you genius' come in) I no longer here the pop of the sudden motion sensor. Usually upon moving the laptop from a table to my lap etc it would instinctively lift the drive head. I now hear nothing. I've tried every type of dangerous knee jerks with the macbook within reason. The SMS doesn't seem to respond, even though terminal tells me its on. Is their anyway way to check this or reason as to why it doesn't seem to be working? Even stranger, when I tilt or move from Macbook, the harddrive sounds like a lightsaber. Its quite awesome, but also a little terrifying. I dont think this is normal. If anyone can give a reason or a similar experience with this, that would be great. Cheers for the help guys.