just discovered with a live chat with a customers. please check if your wordpress template doesn't use an old version of jquery ( 1.2.3 )

just make sure you have a recent version of jquery

for example
look in the source page and of the template and replace any reference to local jquery to a hosted version

http://docs.jquery.com/Downloading_j..._Hosted_jQuery

so you could check if it is the source of the problem.

if it is still not working, please contact Wp subscribers support