[Plugin: Portfolio Slideshow Pro] slideshow not working

I just installed this plugin today, and created my first slideshow from images that were in my Media Library. Where the slideshow should be, I see the first image and all of the thumbnails, but the thumbnails are dimmer. I can’t get the slideshow to move forward or backward and I can’t select any of the images from the thumbnails.

Slideshow is at http://www.whetstone.wesley.edu/practice/2014/01/24/integrated-media-class-post/#slideshow

Code in the post is [portfolio_slideshow id=4165 trans=fade showcaps=true loop=true click=lightbox]

I think I’m making some kind of obvious beginner’s mistake with the slideshow, but I can’t figure out what it is. Does anyone have any ideas?