Originally Posted by DoctorVideo
Yes, I'm having the same issue. Now if your problem occurs with the sound coming out of your A/V receiver, that is pretty normal and can usually be adjusted in the menu settings of your receiver. In my case, I am having problems with the sound coming directly from the TV speakers. I have an HDMI connection to the TV from my DirecTV DVR. The problem is intermittent. It can be dead-on accurate when I first turn on a program, and within 30 minutes, it will be noticeably off. Sometimes commercials will be out-of-sync, but the program will be in-sync. Just now, I noticed that the sync was off. I switched to the on-line user manual to check something, and when I switched back to the program, it was back in sync. The same thing will often happen if I switch channels and then go back. It's a head scratcher. Even though this all started when I got this TV, I contacted DirecTV to see if the problem could be on their end. They did a deep reset of my system, and the problem disappeared for a few days. Now, it's back again, so I don't know what to make of it. Are you by chance a DirecTV subscriber?
Try changing to Game Mode, with smooth motion off, and see if the problem persists. I'm wondering if the "processing" the TV does in the background may use up a few milliseconds, and starts to get behind a little.
I've also noticed this same problem-both on the M501 and M601-and the Lip sync only makes it worse. It's intermittent, and I use Dish, HDMI into the TV, then Optical out of the TV into a Vizio Sound bar(no adjustment on that). I notice it in live broadcasts, and in DVR broadcasts. My normal routine is to turn the sound bar on, after programming has started on the TV. Sometimes, when it goes out of sync, I'll pause the program, turn the sound bar off, then back on, and it will be synced. Other times-no so much.
I've not noticed this problem too much while playing movies via the HDMI cable from my laptop.