I work on a project with various video clips on my older desktop computer running Windows XP working off a portable Hard Drive, then I open the same project on my newer laptop running Vista and some of the audio files are gone. The video is fine on both. I know the audio stream is there in the mpg file (I think it happens with AVI files too) but Vegas Movie Studio on the laptop doesn't display the audio track and it doesn't play in preview mode.

I'm not sure yet but I think the Audio is there after I render and open the resulting file in DVD Architect.

Some setting need to be changed or missing codec? I looked at Preferences and Properties in both computers and they appear to be set the same.