Why would I want multiple slide sources ?
Different types of slide source have different uses. Flash based slides are ideal for the main slide display, but are unsuitable for the thumbnails and printing. Image based slides are better for printing and thumbnails and can also be used in place of the Flash slides in the main slide display if the flash plugin is missing. PDF slides provide an additional option for printable slides. Multiple slide sources also allow you to have translated versions of slides for other languages on the same presentation page.