I just got hooked up to HD a week or so (Moto 6200 box) and I'm getting lip sync problems. I and the comcast guys have tried various configurations to identify where the problem comes from, but it's really tough.
Some channels have no problems (ESPNHD, for example). Others have problems some times (NBCHD was terrible during Ryder Cup). And not just the HD channels either. I was watching "Parent Trap" on the Hallmark channel the other day (OK, I'm a sucker for Haley Mills), and the movie was out of sync, but the commercials were in sync -- on the same channel. When the problems occur, the video is behind the audio (about 100-140ms).
My current configuration is to route digital audio to my receiver (Rotel) and to route component video to my receiver and then to the TV (receiver has video switching capability). I first suspected the video switcher as culprit, but taking video direct to TV (Sammy HLP 56") had no effect. The only way I've been able to eliminate the problem is to take standard coax cable out of the 6200 and into the back of my TV, which sort of defeats the entire purpose. Whenever I connect the digital audio on the 6200 (either digital coax or optical) to the reciever, I get lip sync problems on some channels some of the time.
Comcast now seems to think that others are experiencing this problem and that it may be at the "head end" (or something like that, where they mix the feeds into the cable). Are any of you experiencing problems like this with Portland Comcast? The problems seem weird enough to me that I can't convince myself that any one is really at fault.
Thanks much in advance for any insight you might have. I've learned a lot from reading the posts here.