Sequence of the slides is not valid (in Thumbnails too). (i suppose one after another slides (1,2,3...))
Please check http://www.aspose.com/forums/ShowPost.aspx?PostID=10717.
Order of slides the same as in ppt file.
I wouldn’t like to sort it because a lot of internal records must be reordered in this case.
You can use SortedArray and sort slides by SlidePosition.