Ok speravo che fosse un semplice accorgimento
codice:
public void addFrame(JInternalFrame frame){
lastsel = desktopPane2.getSelectedFrame();
if(x_iframe > 3*desktopPane2.getWidth()/5) x_iframe = 0;
if(y_iframe > desktopPane2.getHeight()/3) y_iframe = 0;
frame.setBounds(x_iframe, y_iframe, frame.getWidth(), frame.getHeight());
desktopPane2.add(frame,JLayeredPane.DEFAULT_LAYER);
desktopPane2.setSelectedFrame(frame);
frame.toFront();
x_iframe+=5;
y_iframe+=10;
for(int i = 0; i < desktopPane2.getAllFrames().length-1; i++){
System.out.println(desktopPane2.getAllFrames()[i].getName());
desktopPane2.getAllFrames()[i].toBack();
desktopPane2.getAllFrames()[i].setMaximizable(true);
}
desktopPane2.getAllFrames()[desktopPane2.getAllFrames().length-1].toFront();
}