My Book Studio Edition shuts off by itself

I have a PowerBook Firewire (the last one before the Intel chip) and OS 10.4.11. A couple of months ago I got a My Book Studio Edition 1 TB. I’m using the Firewire 800 connection. Over the last couple of weeks I find it randomly shuts off and its icon disappears from my desktop.Or sometimes out of nowhere I get an errror message that the HD is not allowed to shut off because it’s in use - and then it doesn’t continue shutting off.  It seems to happen when I’m opening a folder or clicking a triangle to show the contents of a folder, but I’m not certain that’s the only time it happens. The colored beachball spins and then the drive is gone. I have whatever software version came with the drive; I’ve never been told to update it. But then, my OS is far from the newest, either.

Can anyone help me?

you definitely want to go to and download the software update and the firmware update. I just bought  my drive and was seeing on before I bought it to do so.