Try using BeyondCompare to make the copy between the Fireball and the PC drive.
BC will create a "worklist" of files to be moved and then start the copy, when it fails, you can just restart it from the failure point and pick up from there.

The Fireball drive is probably failing and breaking the copy, so this will let you run the process until you have everything copied or the drive fails completely.

http://www.scootersoftware.com/