I need to replace the HD on a MBP 4,1 (Early 2008/Penryn) as SMART recently started throwing errors. I just ordered a 640GB Samsung Spinpoint M7E after having read about all of the issues on the WD Scorpio Blue 640GBs with MBPs. Then someone in the Apple Support Forums mentioned in this thread that the same issue exists for the Samsung as well (and supposedly the Seagate). Has anyone tried the Samsung 640 on their MBP? If so, did you have the power management, load cycling and other issues? Fry's is running a sale on the Hitachi 500GB for about $55 bucks right now. I'm thinking maybe that I should just cancel the Newegg order and grab the Hitachi.