Trolling through the DishTV website and I saw a new firmware loaded today for the S7010PVR. It had a problem with Western Digital Elements USB HDD enclosures, both the 1Tb and the 1.5TB versions. It wouldn't recognise the HDD if you used that enclosure.

It looks like a fix has been found http://www.dishtv.co.nz/S7010PVR.htm 

I don't have this model myself, but I know quite a few others here on the forum have had this problem. Any feedback on whether it fixes it?