duplicateMovieClip problems

I have a MovieClip on the canvas called square.

[color=darkred]var holder:MovieClip = square.createEmptyMovieClip(“holder”, 1);[/color]

Now I have a MovieClip inside of square called holder

[color=darkred]square.holder.attachMovie(“circle”, “circleNew”, 1);[/color]

circle is from the library and is attached, that works, but below does not work, what gives?

[color=darkred]square.holder.duplicateMovieClip(“holder2”, 5001, {_x:25, _y:50});[/color]
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[color=darkolivegreen]Why does the duplicate not work?[/color]
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