I've just uploaded a test set of images to a Flickr account in order to test this and flickrSort="DATE-POSTED-DESC" (and flickrSort="DATE-POSTED-ASC") works as expected on my test set.
However, I've tried it on your 'corps' set and although DATE-POSTED-DESC and DATE-POSTED-ASC both produce different (and consistent) orders for the images, they are not completely reversed.
It's just a thought but, perhaps, if several images within the set finished uploading at the same time, then the order of this batch might remain the same within the set no matter whether DATE-POSTED-DESC or DATE-POSTED-ASC is used.
You could try rearranging the images within Flickr itself (using http://www.flickr.com/photos/organize/ ) and use the flickrSetId option which overrides the flickrUserName and flickrTags and will use the Flickr set display order. (To get a Flickr set id, go to the set's Flickr page. The id is the last numerical string in the URL.)
You may already have discovered the following pages but I'll include links to them as a reference:
SimpleViewer Pro Flickr options:
http://simpleviewer.net/simpleviewer/pr … tml#flickr
Here are a couple of FAQ on Flickr that might be useful:
http://simpleviewer.net/simpleviewer/su … #general_5
I hope these suggestions and links prove useful.
SimpleViewer Support Team.