Assistance unloading flv's from swf's imported to main stage

Question

I have my main.fla which imports external swfs that contain flv's. I have three buttons that navigate the main timeline to frames 2-4. At frames 2-4 an external swf gets loaded into an empty movie clip via this code. Each loaded swf acts like a menu with some nice vidoes loading in the background.
The problem i found is the flvs continue to play as i navigate between menus, which makes the main swf/fla slow down becuase the pc is working harder to deliver all the stuff running in the background. I've added this code to frame 1 of my empty movie clip that is in my library that has the instance name 'menu1'
I keep getting the error "Access of undefines property mc1"
I have the source files for my site here if you can take a look and see what I'm doing wrong. I have removed this code so i don't get the error and have tried other things to no avial.
http://www.coldbloodedsovereignty.com/site.zip
var loader:Loader = new Loader();
addChild(loader);
loader.load(new URLRequest(MovieClip(this.parent).src));
var src:String="external.swf";
menu1.addEventListener(Event.REMOVED_FROM_STAGE,f);
function f(e:Event):void{
MovieClip(e.target).loader.unloadAndStop();

Answer 1

consider the files gifts to those willing to help, should they choose to use them for their own. oops, yes the files were created in cs5.
I will try your suggestions tonight. Thank you.