I have a Voyager enclosure attached to my mac pro via eSata, with a WD 2 TB drive in it right now. I'm copying about 500 GB of media from one of the internal drives to the Voyager, and I'm seeing a copy speed of 4 MB/s, which is incredibly slow. It's telling me it will take "about a day" to copy 500 GBs. That's not right. Any idea what could cause a slow down like this?