Loading Random SWF file problems

filename = ["header1.swf", "header2.swf", "header3.swf", "header4.swf", "header5.swf"];
path = "[www.domain.com/images](http://www.domain.com/images)";
i = filename.length;
k = Math.floor(Math.random()*i);
loadMovie(path+filename[k], movieTarget); 

That is the code that I am using for the container swf. I know the code works because I used it for static images and it worked fine. When I take a look and the HTML file, this is the error I get.

" A script in this movie is causing Macromedia FLash Player 7 to run slowly. If it continues to run, your computer may become unresponsive."

each of the header swf files are about 40k, and they each load AS from a single AS file. Do I need a preloader? Does anyone have any ideas?