My parents finally bought an HDTV! I am about to call and order service for them from D* and have a question. They are getting 1 HD DVR, 1 HD receiver and 2 D12s with the MRV service. If later we buy a MRV capable receiver (an owned H or HR), is there an amount of service time that the D12s have to be on or can they be replaced, deactivated, and sent back right away? I would assume they need to be on for a length of time since they would end up on the "FedEx refurb truck", but I figured I would ask. We may go ahead and just lease another H receiver when we set this up.