I have experienced the same A/V sync issue with my Sony BX450 LCD and the Vizio 215 soundbar. The A/V sync has nothing to do with the Vizio 215 but its the TV that is causing the issue. I have my soundbar hooked up to my tv via optical cable and everything else is hooked up to my TV via hdmi. I'm experiencing A/V sync problem with my bluray and the DISH receiver. But if you try connecting the bluray or the Dish receiver directly to the soundbar, there is no more sync issues.
Here's a solution:
My guess is that you are bitstreaming the audio to your soundbar? If you are, go back to your devices and switch them to PCM. That should fix the A/V sync problem because when we Bitstream, some tvs aren't fast enough to process it quickly enough to pass it through to the soundbar.