I have noticed some problems getting both my 722k and 612k seeing the exterrnal hard drive I have saved some movies to. I called Dish for another reason and asked the tech. He said that external hard drive will work from the front USB port but not the back. The back is for sling adapter or wifi adapter. This would explain why my drive doesn't work in the back, but this was news to me, had not heard the two ports were in any way different. I am using a WD 500 Scorpio Black with no AC adapter, so I wonder if this is true if the drive is not powered from the port, but from AC instead.