just got myself a western digital my book pro 500gb external hard drive but however hard i try (searching the WD faqs/forums) i cannot get a definitive on whether the intelligent drive managment feature of turning on/off automatically to the behaviour of my MBP is applicable with a firewire 400/800 connection. the HD will only power off completely when connected to a USB interface but not on the firewire 400/800 ones. when i connect the HD on firewire 800 and turn the MBP off, it emits a pulse every 5 seconds... granted that the HD seems off as there are no audible activity when i put my ears near it but why is it able to power off completely on the usb connection and not on a firewire one? it's a little strange. is there something wrong with my hard drive or is it one of those unmentioned glitches? i bought the hard drive for the firewire 800 interface and the auto on/off feature but it's very disappointing when the latter does not function as advertised. any one has experiences with the My Book range of hard drives and are able to offer a little perspective?