Having just purchased a 2.4 Ghz Unibody Macbook I'm looking to replace the hdd. Having answered a question on SATA I was searching for a suitable hard drive and found the Seagate momentus 7200.4 500gb drive. Reading through the reviews on newegg I spotted someone talking about issues with the unibody macbook's motion sensor here (about three down) - Having read that I searched the forums and found a couple of threads that have me concerned. This one for instance mentions that whilst the drive works well it no longer parks under sudden movement. Likewise this thread saying sales have been suspended, possibly due to the above issue. -- With those things in mind I was wondering if anyone could clarify which hard drives are compatible in this way with the macbook? Since reading this info I've been looking at the - WD Scorpio Black 320GB - Seagate Momentus 7200.3 320gb I don't strictly speaking need 500Gb of space so I'd rather give the problems a miss, unless I can guarantee I'm getting a drive that'll do the job and won't sacrifice stability. With that in mind, reading what people have said on here I'm tempted to go for the WD Scorpio. However I notice that this drive is offered with and without the "free-fall sensor". I guess my question is which model would suit the macbook and ideally will still park the heads if the MB moves suddenly. Does anyone have one of the Scorpio drives installed in a unibody macbook and can they please confirm that the heads still park?