Switch from S/PDIF output to HDMI output in your BIOS settings (onboard device configuration, audio sound or something).
btw S/PDIF cannot transfer hd-audio, it will be downmixed in realtime to lower quality; maybe in action scenes with loud sound and higher audio bitrate your pc/soundcard is to slow for that or has other timing issues
EDIT: maybe also try turning off sound in PDVD (not the TV) completely testwise and watch the problematic scenes; if they are fine then, it's very likely an audio issue though i must admit having no clue how to solve it then
This message was edited 2 times. Last update was at Apr 10. 2012 08:41