Dynamic created button resizing

Question

I have created buttons dynamically:

CButton* m_btn = new CButton();
m_btn->Create(csIconText, BS_FLAT|WS_VISIBLE|WS_CHILD|BS_PUSHBUTTON|BS_ICON, 
              CRect(0, 0, 80, 80, 8001);

...after creating a button and resizing it:

CButton* btn = (CButton*)GetDlgItem(8001);
btn->SetWindowPos(0, 0, 0, 50, 50, SWP_FRAMECHANGED | SWP_NOZORDER )

...it works fine. I can see the button with the new size on the dialog.

But when I save this and open the dialog the button is not displaying on the dialog. It is hidden. Why is that happening?