I switched mine to sd sync and my lip synch problems went away on my 722. That and I have an audio synchronization feature on my Sony A/v receiver and it is set to 2 which gets me in synch on both tv and a/v .
I have only seen the sync issue on my local NBC affiliate which is notoriously bad about providing quality broadcasts in any event. I went ahead and sent an e-mail to DISH Quality as the problems on NBC seem to be exaggerated by the MPEG2 to MPEG4 transcoding process. Given some of the issues I have had transcoding digital content on my home PC, this does not come as a big surprise to me.
I get it a lot on my local NBC over the satellite, but not OTA. I also had it bad yesterday on the new HistoryHD, never cleared up, and many others complained about it. It happens on MonstersHD sporadically.
I see it almost exclusively with my local NBC affiliate. After a few minutes, it seems to sync up. Fortunately, at least in my case, the only thing I watch on NBC is "The Office".