There is a bug that has been around since Mac 10.3 OSX was released and is scaring the pants off the new leopard users.  The bug occurs when a user is doing an move operation, and a network, USB, or FireWire drive is disconnected. The result is that the user could loose huge amounts of data, with an unstable drive. The faulty hard drives seem to all be Seagate 2.5 drives that are made in china like nothing isn’t joking we love you China. They are also all SATA interface. The error makes the head clash with the platter. This bug has been around since the 10.3 times.