In Photoshop Elements 8 & 10 Organizer, images were placed in an image stack in the reverse order in which they were selected, that is the first image selected was at the bottom of the stack and the last image selected was placed at the top of the stack. This was a convenient behavior even if it wasn't done intentionally. With Photoshop Elements 11 Organizer the files are no longer stacked by the order in which they were selected. What appears to happen is that the last image selected is put on the top of the stack and the other images appear in sequence by (date or filename?) irrespective of the order in which they were selected. There are times when this behavior requires me to manually perform extra steps to move some files to the top of the stack and do it in a order than will create the final stack order I desire.