VideoStudio :: Sound Distortion On Burned Disk Playback

Completed my film, created video file and burned it successfully. For this film I used copyright free music. Unfortunately, when playing back the burned disk, the sound "skids" and sounds somewhat distorted in places. Less so but still distorted is some of the spoken word in the film (ie the person on the film not voiceover). (Everything is fine when playing back the project in VS.) It's not so bad you can't play or hear it but obviously not satisfactory to my own pride! - letalone the viewer.

I do not use the "normalise audio" function and wonder if this would make a difference? I had presumed until now that the normalise audio function would merely make all audio the same level - on whatever work I had done to make the sound/voice overs different, e.g. lowering sound at the point of voice-over etc. I should say I have used a lot of visual effects in the film - 6 overlay tracks - and wonder if I have exceeded the bounds of sensibility!