The coordinates of a MC

When I use:
_root.mc1._x=0
the MC appears on the top left corner of the screen
but when I import a movie using loadMovie(), the coordinates are different
_root.container.loadMovie(“mc1.swf”,1)
_root.container._x=0
this time it’s not on the top left corner of the screen.
Does anyone know how to place the MC correctly on the stage?
thanks