But seriously, it does occur and I have experienced it in the past. And was very anooyed by it, as you are. Lately I have not been paying attention to it, so I can't recall if it is still happening. I will have to start watching for it again. It is annoying and can ruin a HD experience.
That setting isn't new. It has been in the menu for years now. It doesn't make sense though. If it's set for HD does that mean the sync is going to be off for everything in SD? There should not have to be a choice here. All audio should sync with video no matter what the resolution is set to.
I have frequent lip sync issues and it's really annoying. It has got to the point where I can't "not" analyze the lip sync on everything I watch. It sounds ridiculous, but I have even caught myself at work listening to someone talk from across the room and expecting their voice not to match their lip movements.