did you ever figure it out I am having same problem thanks
Are you referring to audio and video being out of sync? If so, how are your components (TV, audio system, set-top box) interconnected?
Does the problem go away if you change "Settings / Device Settings / Audio / HDMI Audio Output" on the set-top box to Stereo? If that "fixes" it, does A/V remain in sync if you change the setting back to Auto Detect?