Problems with my site

Hi I have a strange problem with my site As you can see none of the buttons work. I’m used the Dynamic transitions and preloader tutorial for the basic ideas of the site. However I have noticed that when the main index .swf is played in the standalone flash player the buttons work however when it is played in a browser they don’t.

Heres a link to the files to test it
Can anyone work out why they don’t work in a browser cos its driving me crazy!!