Actionscript problem

I am trying to create a site that has an swf file on the homepage and when the buttons are clicked, I used the loadMovie code to included other files (to make the whole file size smaller). It is working fine, except the “portfolio” button when pushed the first time acts as normal but if you click the other 2 buttons and then come back to it, it won’t work… (there is a book that you are supposed to be able to open - the first time you can & the second time you can’t). The only way to open the book again is refreshing the browser. Some help would really be appreciated!

Here’s where you can see what I’m talking about:
www.pauline-alexander.com

Here’s the code I used:

on (press, release) {
loadMovieNum(“portfolio_book.swf”, 50);
}
on (release) {
unloadMovieNum(40);
}
on (release) {
unloadMovieNum(30);
}