buggy duplicateMovieClip

I tried to duplicate a movie clip, but it doesn't work at all, the new movie Clip never appears at the right position, the new Clips don't stay long (until the next one appears), the new movie clips appear only every second mouse click...
it doesn't work properly at all.
My Code is out of the Flash help, I just removed this raandomized crap, the loop and the scale/alpha adjustments.

this is the code:

on (release)
{
duplicateMovieClip (_root.mc, "mc"+i, i);
setProperty ("mc"+i, _x, 50));
setProperty ("mc"+i, _y, 50));
i++;

}

what is wrong with this thing?

without being able to see it, i can only guess.

you have an extra ")" on the setProperty lines.
it should be: setProperty ("mc"+i, _x, 50);

the question is: how do you want your new movie clips to appear on stage?

because with that script, the line i++; isn't exactly doing anything unless you put the whole thing inside a conditional statement.