What are you signal levels on the HD channels . I have found before that if a strong enough signal is not there for hd channels then part of the electronic control message (ecm) is missed causing freezing and glitching and higher ecm times. This is documented in other forums. I had badly aligned 28.2 and on espn hd i would get glitching/freezing and high ecm times. When i got a sat company to align dish correctly the problem went away . Just a thought . report back your signal levels
regards
t