setBackground does nothing?

Every time I am using to beautify my BlackBerry screens with a background I trap into the same pitfall. Over and over again.

Her it is:

Simply trying to set the background colorr for a Screen instance:

myScreen = new MainScreen();
myScreen.setBackground(BackgroundFactory.createLinearGradientBackground(Color.BLACK, Color.BLACK, Color.ORANGE, Color.ORANGE));

But when you push this screen to the display stack there will be nothing but a white screen.

Remember to do this like this:

myScreen = new MainScreen();
myScreen.getMainManager().setBackground(BackgroundFactory.createLinearGradientBackground(Color.BLACK, Color.BLACK, Color.ORANGE, Color.ORANGE));