The bizzare thing with my busted drive is that (due to a shortage of USB ports) I have the optical mouse plugged into the one of the usb ports on the HD (and I download my pics in the other) and it works fine, so there doesnt appear to be a power supply problem, its just that my pc cannot find the HD (G:\).
Ive tried installing it again with the CD, and even tried installing it on my sons laptop to no avail :-(