Problem with loaded MC position

Dear perople of Kirupa

I have a flash project:

On the stage I have created an empty MC for loading all my content. As the page loads an MC from the library is loaded in the empty MC. Then when I click a button from the menu external swf files are loaded into the empty MC.

The problem:

The first MC to load (when the page is opened) loads in the top left corner of the stage (as thought the registation point is different).

Can anyone help or am I doing this the wrong way?

many thanks!