This is kind of wierd. I always have to do lip reading in order to understand dialog, or else use the close caption feature. On my Insignia, most of the time the audio is not in sync with the video. It's really wierd trying to watch somone speak when the voice is not on track with the lips. Anybody else notice this? I think you have to be hearing impaired to notice it. Is it just the Insignia doing this?
You're probably experiencing the CECB decoder audio/video going out of sync. I've experience this problem with all CECB's that I've tested. It usually happens when the incoming "Signal Quality" (not "Signal Level") drops to it's threshold level. Usually, I find the problem gets resolved by power cycling the CECB. If the "Signal Quality" stays low, you may have the problem reappear.