If you experience that the audio and video are out of sync, verify if the HTS has an audio delay feature and make the required adjustments. The TV itself does not have an option to set the audio and video delay.
Since a video signal is more complex than an audio signal, the TV will take longer to process. Due to this difference in processing time, your HTS may reproduce the sound before the picture appears on your TV.
Some Home Theater Systems are equipped with a feature named 'audio delay' (or 'Lipsync' or 'audio sync') that will delay the audio signal in order to compensate for this difference in processing time.