It happens with my HR23-700, especially the other night on Disney first half hour of a show was unwatchable because drop in and out really fast then it cleared up.
If you do find out the receiver is bad make them replace after you get protection plan because you pay for it so use it because they will take old receiver and fix it and someone else will end up with it.
Directv said they will deliver 30 hd channels, they will. Not as easy as some people think. They can't make everyone happy. You give them time they will have some hd for everyone.