Alright, I've been searching for hours and can't find any resolution, so will give these forums a shot.
I just purchased a 55VT60 and have immediately noticed an audio lag for everything I've hooked up - cable, blu-ray, xbox one and ps3. I've tried everything I can think of: ran the hdmi straight to the TV to use internal speakers, ran hdmi to tv and used an optical cable to my receiver, ran all hdmi through my receiver passed the signal through to tv, replaced my hdmi cables, updated firmware, tried various modes like standard & THX cinema, etc. Nothing is working. My receiver has the ability to delay the audio further up to 9 frames, but not to delay the video signal which seems to be what is needed.
My setup works just fine with an 8 year old dlp and with a brand new 60" LED SmartTV...so it has to be the Panasonic. Based on my research, I'm starting to wonder if my model is defective.
The picture on this TV is amazing, but the out of sync sound is a deal breaker. I'm really hoping someone can help because I don't want to return it!