I added the Slideshow plugin by StefanBoonstra (v2.2.23) this morning to a site, and there seems to be a conflict between this plugin and the All in One Event Calendar by Time.ly.
If the event calendar app is deactivated (not a long-term solution by any means), the slideshow will work.
Maybe some kind of javascript conflict? Could you please take a look?
http://www.stnicholasfreedom.org/parish
Thanks a ton!
~Karen