Unloading external SWF file

Hi all,
I’ve been a long-time lurker, first time poster. I have a master swf file which loads an external swf file (“Slideshow-main.swf”) into an empty movie clip (“slideshow”) when it reaches a certain point in the timeline.

The external file is called by this:

slideshow.loadMovie("Slideshow-main.swf");

and that works fine, the movie starts as expected. The problem comes when you navigate away from this frame in the master movie and come back to this slideshow. It appears that the previous loading of the movie is still running and overlaps with the new loading, thus creating a mish-mash of stuff. I have tried almost everything and can get the movie to unload using:

slideshow.unloadMovie();

However, when the movie starts back up it does the overlapping thing again. I have searched the forums and all over, but to no avail.

Thank you for any help!