Problem with imported movieclips?

Ok ive got 2 movieclips one called Importer and another called Background and basicly i want to set Background to the same height as Importer because its importent for the layout .

So ive got

Importer.loadMovie(Link); //Specified in xml
trace(Importer._height); // Awalys remains the same bizarly even when loaded
Background._height = 10 + Importer._height;

My poblem is that the Importer._height dosnt seems to be changeing when i load another movieclip in it should change to 150 and set the background height to 150 .

Very strange because the swfs movies arnt distorted even though their height is tracing at 30

Any ideas ?