[Plugin: NextGEN Gallery] Slideshow displays only white box

I’ve searched for a solution and have not been able to resolve the problem. Only the slideshow feature doesn’t work. It displays just a white box where the slideshow should appear. I’m on Firefox, WP 2.8.4. Here’s the page where the problem exists:

http://d6749745.u51.websitesource.net/iida/

I’ve used this plugin before on other sites and it has always worked like a charm especially after I fixed the common problems. So, I think it is installed correctly? Any new ideas most appreciated!

Thanks,
Sharon