You can view the site here:
I've been using the code from the 5th example on the Galleriffic site, here:
I thought it might be something to do with my CSS overriding the Galleriffic CSS, but I temporarily commented out my CSS link, and it still has the same problem.
I would be very grateful for any help anybody can give. If you know of another JQuery slideshow that works in a similar way to the one on this page:
then I will try that instead.