Duplicate a once invisible mc

Please show me how to correctly duplicate a movie which has previously been set to invisible. See commented out lines in the attached fla. Just show on the penny_mc,
Also, I could use suggestions on how to assign the movies which hit their targets a number value, and then keep a running total of all hits in a container, and display the content of the container into the dynamic text field. I am very slow to learn this, and could realy use the explanations commented out along side. Thanks.
the movie is not duplicating, but the screen is heightened, for some inexplicable reason.
if (display1 == true ) {
penny_mc._visible =0;
duplicateMovieClip(_parent.penny_mc, new penny_mc, 1);

setProperty (new penny_mc, _x, 10);
setProperty (new penny_mc, _y, 267);

setProperty (new penny_mc, _visible, true);

}else{
penny_mc._visible =1;
}