I had to schedule an appointment to have my box replaced. This will be the 3rd box in 6 months. That is unacceptable. When Comcast comes out with a whole house DVR in my area I will be switching providers.
You may want to first check the wiring/electrical service in your house, particularly the outlets where the boxes have gone bad. Agree, replacing 3 boxes is unacceptable, but if you are having ground problems in your outlet(s) the equipment will fail prematurely.
You can buy an inexpensive tester (under $10) at any Lowes, Home Depot, local Hwd, etc..
Also check the NID (gray phone box on side of house) and make sure there is a ground wire going from the box to a grounding rod.
If you get to thinking you're a person of influence, try ordering someone else's dog around.