Background sound problems driving me crazy!

Everything in my site works fine, until the navigation buttons are clicked a few times, then the background music restarts and plays over the music that is already playing, sometimes creating 3 or 4 instances of the same music all playing at different times. Any one have any idea why this is happening?

I do have a music control (start/stop) button, it’s a movie clip with 2 frames (the first with music and the second to stop all sounds) that I placed into a button symbol…

You can check out the site at http://www.bol.ucla.edu/~lynette/flashtesting/testintro.swf

Thanks for any insight into this…