Hi Peter, thanks for taking the time and trouble to reply. In fact I had tried what you suggested but it made no difference. However I have got a solution by doing it in a different way. Previously I added the Sound using the "Add Sound or Voice" at the top of the slide preview. No joy. By using the Customise Slide, Music Tab, Add Music it works just fine. Perhaps I should have been doing this all along? Anyway, I'm happy.