Yesterday i upgraded from iPhoto 5 to iPhoto 6. Most of my 15,000 images vanished, including those in numerous folders. When I click on the white space (which has a square in the center) I get a gray square with an intermittent white line. In the center is a small black circle with an exclaimation mark which almost fills the circle. I am an essayist and luckily made DVD's of the very best images. But the second or third stringers are also very good. Are the images retreivable? They represent 5 years of work. I have recently lost my health and could never hope to replicate the shots. Any help would be greatly appreciated. Thanks in advance.