Passport studio won't turn off after shutdown Mac mini

Hello. Recently I have bought a wd my passport studio 320gb. I’m connecting it through the firewire 800 in my Mac mini. No problems with it but only one. My disk stays in standby mode when I turn off my Mac mini. Is this normal? Is WD going to make a firmware update for this?

This is happening because Macs continue to supply power through the firewire ports when they’ve been turned off.  As a result, the drive thinks the computer is still on, so it waits in standby.  Try removing the drive before you turn off your Mac and see if that helps.