On MToolkit a Window shown before its decorated owner is not focusable.
The bug may be reproduced with the following testcase:

import java.awt.*;
import java.awt.event.*;

public class WindowTest {
    static Frame frame = new Frame();
    static Window window = new Window(frame);
    static TextField textfield = new TextField();

    public static void main(String[] args) {
frame.setSize(100, 100);

window.add(textfield, BorderLayout.NORTH);
window.setBounds(0, 200, 200, 200);

window.setVisible(true);
frame.setVisible(true);
    }
}

Compile and run the test on MToolkit. You will see a Window with a TextField and a Frame
appeared. Try to type in the TextField. If no text can be input the bug is reproduced.