I have a Fantom Drive external drive, 60 GB, circa 2007, I use for backup. I only turn it on occasionally. Sometimes it will appear on my Mac Mini desktop (1.25 Power PC G4, 512MB), but most of the time it will not. It tends to appear after I have not used it for months. But then it will disappear from the desktop after a while. Maybe it's a heat problem? I've tried plugging in the external drive to different ports (it has a USB cable) and unplugging all over devices. Plugging it into my Macbook--there I get a message of USB Over Current and it disables the USB port.