Thank you for providing the URL to your gallery.
It looks like your gallery thumbnails have not been uploaded to the correct location on your web server.
According to your gallery's XML file, the first thumbnail in your gallery should be located here:
However, going directly to this location in a browser results in an error 404 (file not found).
If a thumbURL leads to a missing image, the Flash Player within SimpleViewer will use the corresponding imageURL instead but the Mobile Player (used to display galleries on mobile devices) will not. This would explain why images are displayed in Flash presentations of the gallery but not on your iPad or iPhone.
Please check that the thumbnails for your gallery have been uploaded to the correct location on your web server (the http://www.villachateau.com.au/thumbs/ directory).
If they are there, then check the references to them (the thumbURL entries) in your gallery's XML file and check the permissions of the 'thumbs' folder and the thumbnail images themselves on your web server. Default permissions of 755 for folders and 644 for files should work fine.
SimpleViewer Support Team.