OS X V10.6 Snow Leopard :: Multiple External Drives Failed

This is the third drive that has failed since I was assigned this Mac Pro at work a few weeks ago, and the drive was purchased less than a week ago. The other two were older drives. They would suddenly stop being readable. Sometimes there was a problem ejecting the drive before it stopped becomeing readable (message would say the drive couldn't be ejected because another program is using it, when there were no programs open). One of them eventually mounted again and I recovered some of the files (but some files weren't readable when I tried to copy them). But that was just luck as they all seem now to be consistently unreadable. When I plug them in I get the message: "The disk you inserted was not readable by this computer". same if I plug it into a different computer. And when I try to repair, it shows this: http://i.imgur.com/ivK9d.png. When it happed to the second drive, I just thought it was a fluke... but now a third, brand new drive? Something about the computer must be causing it.