Using Preview's Slideshow, Add to iPhoto does nothing

Preview has a SlideShow feature under the View menu. Using it to page through a PDF file I've printed from Excel, I've noticed the tools that appear at the bottom of the screen include an "Add to iPhoto" icon. When I click it, it highlights briefly, but nothing else seems to happen, and nothing gets added to iPhoto. Does anyone have any suggestions? I'm trying to get images to post to a wiki, and this seemed like a particularly efficient way to do it...if it would only work.