Blank screen in game after automatic keypad lock in nokia S40

Question

After the automatic keypad lock, when I unlock it, there appears a blank white screen and after 3-4 seconds, the game field appears. Any ideas, how to avoid this behaviour? I want that the game canvas should be immediately displayed after the unlock.

Update:

Here is my startApp method:

public void startApp() {
   start();
}

 public void start() {

 instance = this;

display = Display.getDisplay(this);
display.setCurrent(myGame);
 }