I bought a 721 yesterday. Activation was a pain, but after it was all set up, I loved it. This morning at 5:30 a.m. my dog started barking. So, I got out of bed and checked it out. She was standing under the BRAND NEW 721 barking at it. It was making clicking noise. I turned on the TV and Low and behold, there was a message saying that my disk had failed. After sever attempts at rebooting I called Dish. They are sending me a new one and said this was "certainly not a common problem". Any thoughts?