I have had a Seagate external HDD plugged in to my G5 Mac for perhaps a year without incident. Ironically, I had purchased it to be my backup. Recently, its image stopped appearing on the desktop when I started up the Mac. It has two places it can plug into it, I think it’s Firewire, but only 1 on the Mac itself. I’m going to try plugging it in to a different computer, but that would be a PC (which hopefully has a Firewire plug in. Fortunately, I think at least most of the documents therein are readable on a PC. Any ideas as to why the Mac stopped recognizing this external drive, which hasn’t been moved or fiddled with since it was plugged in for the very first time???