The sync issues may be an issue with the broadcaster. The television wouldn't fluctuate, so if it was the TV, the issue would be there all the time and consistently. The fact that it varies likely points back to the box or the transmission.
Even with the loaner TV, there's a difference, so that suggests that even if the television is updated or parts are replaced, the issue will still be there as a result of the cable/sat connection.
As for the Blu-Ray player, I'll keep my eye out for similar posts, but I haven't heard of any widely reported problem. Normally I'd suggest trying a different HDMI cable, but that's all I've got at this point.
Keep me posted.
I recently bought a Samsung LN32C650 along with a Samsung BD-C6500 Blu-Ray player. I had some issues with my cable box, and when I thought I had that all figured out, I started noticing lip sync problems with the TV speakers. That's when I started troubleshooting on other message boards.
At first I thought it was the cable box, as I didn't notice it when using my Blu-Ray player or when the coaxial cable was plugged directly into the TV. Some channels were worse than others, but all of them had at least a bit of an issue. I got a new cable box, and the issue was still there. The box is a RNG 110, and was connected with an HDMI cable supplied by Comcast. I also tried using component and a different Monster brand HDMI cable, with no improvement.
Then I started noticing the issue when using my Blu-Ray player too. It wasn't as bad as the cable, but it was still there. The BD player is connected with a Monster HDMI cable. I called Samsung and they didn't have my model in their system yet, and told me to call back in about a week. Both the cable and BD player were plugged directly into the TV, and not any sort of AV receiver, and it seemed to be the audio lagging behind the video, so I pretty much ruled out normal audio lag.
I bought both the TV and BD player and a small but very reputable local mom and pop type store. They have a very good reputation, especially where customer service is concerned, and had good prices. I called them to see if I could exchange the TV for another of the same model, as I hadn't heard about anyone with the same problem with their TVs of the same model on any message boards. The guy who sold me the TV said they had to go through their tech service (which is authorized to service Samsungs) to make sure it wasn't something that could be fixed by "zapping" it. I made the appointment for them to come and pick up my TV.
The night before they came to get the TV, the problem became almost unnoticeable, if not gone completely. They came and picked up my TV, and gave me a loaner. Now I'm worried they are going to tell me there's nothing wrong with it, and give it back just for it to happen again.
There are still certain cable channels that have lip sync problems even on the loaner, but most channels are fine, so I'm guessing that's an issue with the box or cable signal itself.
Can anyone here fill me in on what might be going on?