Is Macbook's Sudden Motion Sensor that sensitive?

Hey guys, I am a new Macbook owner, and also to the Mac world. Today, I abruptly titled my Macbook unibody 2.4 ghz with 320gb hd, and i noticed a clicking sound on the hard drive area.

I did some research and I found out about the sudden motion sensor deal, I learned how to disable it and i tried tilting it abruptly and wala, the clicking sound was gone.. And went ahead and enable the SMS feature, since its recommended to leave it on.

Anyway, I really like this feature, but I guess i just have to get used to the click sound. Nothing major, only when its abrupt or sudden vibration.

It just kinda sensitive, any info on this? I heard the Macbook pro is much sensitive. Is it because my HDD is the same HDD as what the new MBP uses? Please enlighten this noob :)