In addition, if I go to the default folder SonicStagePackages and play any of the tunes they sound fine, it's only when played through SonicStage that the sound is squirrely. That is the best way to describe the sounds I'm hearing, a group of squirrels having a fight , or perhaps some insects swarming, making a hell of a lot of noise.
I've also noticed that the elapsed time of the track being played seems to be correct, in other words the track isn't being played fast, it just sounds as if it is.