652 w/ 2TB drive only reports 47 hrs.

I picked up a 652 with a WD 2TB drive. I looked for the details of the drive and it reports only 47 HD hours capacity.
I opened the unit up thinking it was the original 160 GB drive, but it was the advertised 2TB. The drive is dated 5/09.

I haven't done anything further yet. Whats' up with this?