Screen height changes when the VirtualKeyboard is displayed
The values returned by Graphics.getScreenHeight() and Display.getHeight() will shrink when the VirtualKeyboard is present. If you need to determine the full screen size while the keyboard is present, it may be necessary to cache the full screen dimensions before the keyboard is displayed.
When the VirtualKeyboard disappears the height may not be reset causing the area where the VirtualKeyboard was to not accept focus properly.