Sounds like you're on a Western Arc setup. You're looking at 110/119/129, right? Anyway, all of the HD is on 129 which is a bit lower elevation than the other 2 sats. That means there is a lot more of Earth's atmosphere for the signal to flow through. More atmosphere = more rain between you and the sat in the sky. I dream of a day when Dish removes all SD receivers, SD channels, and spreads the HD love across all the sats (yes, I am kinda high right now..)