navigateToURL "_self" still opens new tab in Firefox

I have a flash intro to a website that I want to redirect to the homepage once the video is finished. My code is below. Everything works right except that it always opens a new tab when I view the website in firefox. It works fine in safari though... I'm pretty new to actionscript but the "_self" command should make the page open in the same tab, right? please let me know what I'm doing wrong!

intro.addEventListener(Event.COMPLETE,completeF);

function completeF(e:Event){

    var targetURL:URLRequest = new URLRequest("home.html");

    navigateToURL(targetURL, "_self");

}