Now I've had a bit more of a play, I can add a bit more context. I am using audio pass through via hdmi, and experience delay of c.250ms for files with non-hd audio (iso and mkv files), whereas the films with hd audio that I've tried are pretty much spot on. Is there a setting I have got wrong, or is there a way to alter the audio delay depending on the audio type present (I don't want to have to adjust the delay in each video when I go into it). When removing passthrough, there doesn't appear to be any audio sync issue.
Any help would be appreciated.
K