I recently got a H21 and now get the Houston LIL HD locals for Houston. I also still get the NY HD MPEG-2 locals that I got the waivers for long before the LIL locals were available. ( I live far enough from Houston I was able to get waivers signed since I cannot get any OTA HD signals )
Anyway sometimes I notice this sync glitch with the Houston HD Channels. The other night it was so bad

I switched to the NY HD feeds and all was well

. From what I've seen so far the Mpeg-2 HD audio feeds at least are superior to Mpeg-4.
I dread when D* takes away my NY locals because I still watch them, especially on my old RCA DTC-210 ird in the bedroom.