I've just tried to make the simplest of all presentations, a basic four slide 'slideshow', consisting of four full (no headers, footers, etc.) images, one image for each slide. The images are 1MB jpegs, imported to the image library using the import icon located on the right of the main screen. The building of the presentation was easy and straightforward, but when I tried to preview it using the dropdown Preview menu, the pictures did not appear in the 'slideshow', although the number of each slide did advance when clicked.
I returned to the main screen and thought to save the presentation first before trying a preview again. As it stands, I have had this screen click here for the past 30 minutes and counting.
Also, the Import option from the File menu will not let me import images, only imp files, maybe that's by design, seems strange though if it is.