Problem with MDI gui

[GiammarcoF]

Hallo there,
I have a problem with my MDI interface.
You can see the picture:
http://img846.imageshack.us/img846/1457/stranoeffettofinestra.png

As you can see when I resize the subwindow, all the edit boxes, images ecc.. seem to be "before" the window's edge.
This is the code I have used to add the subwindow:

MyWidget *MDI::createMdiChild()
{
MyWidget *Mat = new MyWidget (openedFile,0);
Mataz->setAttribute(Qt::WA_DeleteOnClose);
m_ui->mdiArea->addSubWindow(Mat);

return Mat ;
}

I really don't understand where is the problem.
Thank you fo your help!

[stampede]

Does it look ok if you just show() the widget (without adding it into mdi area) ?
Does the MyWidget have a layout ?