Tween w/ resized photo - can't make it work

Greetings from the Flash newby!
I’ve got a tiny test.fla with a movieclip that just moves across the stage. Using a MovieClipLoader to load the clip into myclip_mc it works fine. If I then add some scaling or resizing in onLoadInit() it just sits there. Any way to do what I’m trying to do?
thanks,
Mark