My Book Studio does not shutdown using firewire

I have the My Book Studio 3TB using firewire on imac with OS 10.8.4.  The WD My Book Studio 3TB drive will shutdown as it should when using USB.  However when using the firewire connection the drive does not shutdown when the computer does.  

Anyone having this issue ?

Anyone have a resolution ?

You could try installing the  WD Macintosh +TURBO Drivers

WD Macintosh +TURBO Drivers

Thank-You for the input.  However that has already been installed.

Everything works perfectly when using the USB connection.  I purchased the drive for the firewire connection.  The drive functions on the firewire just like the USB, with the exception that on FIREWIRE the WD 3TB My Book Studio does not shutdown when the iMac is shutdown.  The drive only goes to sleep.  I have to remove the power for it to shut down.

After doing some research verified that this port works like this on Mac.

As opposed to USB, the Firewire ports keep sending power to the drive even when the computer has just been turned off.

The drive will eventually go into hibernation after certain period of inactivity.

You can also disconnect the drive for a complete shut down.

You can search for additional information on the apple support forums.