I have two GoFlex NTFS drives daisy-chained on Firewire 800 bases on an iMac 11,3 (intel) running OS X 10.6.8. I use the version of NTFS for Mac supplied with the drives. I notice that if I put the computer in sleep mode using the menu that the drives turn off as I expect them to. If I let the Energy Saver in System Preferences put the computer to sleep, the drives keep running which I do not want. Is this a problem unique to GoFlex NTFS or is it a problem with the OS?