Hi Nick,
Thank you for using my plugin, and I apologize for the trouble you’re experiencing. That really is a bizarre problem you’re having. Interestingly when I visit the site, my primary browser is Chrome, I can never get the slideshow to work at all, even after cycling through the slides.
Troubleshooting this is probably going to be a pain. Start by disabling your other plugins one by one, testing after each one, to see if it’s a plugin causing the issue. If all of the other plugins are disabled and it’s still causing trouble, it’s probably your theme, but change to a different theme, like twentyten or twentytwelve to see for sure.
Once we have the cause of the conflict, we’ll be able to start narrowing down to how it can be fixed.