Newbie Jquery IE Problem

Hi all, I'm just starting to dabble into the world of jquery.

I've created a slideUp slideDown text list on my site which only shows one piece of information at any time, it works fine in Firefox and Safari however when I open it in IE the show/hide effect doesn't work and you can see all the text.

My site is http://www.bazhodson.co.uk/about.html

Can anyone help?