Sigh - accidentally clicked 'mark as best answer' and there's no way to undo.
Original thread was http://developer.appcelerator.com/question/71231/bug-audio-clipped-on-ios41
John, appreciate the suggestion, but my tests with the simulator still see the sound being chopped off, even with a 1 second delay after the complete event is fired. Preloading the audio doesn't seem to help either.
I had a look at the source code for the Sound object and it does seem pretty simple and thus probably Apple's problem, but I don't know enough about objc dev to be able to say for sure.