I have a customer who had Directv come out for an install, and the tech looked at the coax that was pre-wired and told the customer that copper shielded coax causes the HD channels to have problems. I've never run across copper shielded RG-6 coax in the 9 years I've installed Dish Network and Directv. Has anyone ever had problems with coax that has copper shielding instead of aluminum shielding?