Android :: Notification Manager Doesn't Work With Screen Off

I have a count down timer that when it goes off (to zero) it checks to see if the app has focus. If not it launches a notification in the notification bar. When you click on the notification is re-opens the app. Now all of this works fine but if the screen happens to go off, the timer keeps going and the notification is available at the right time but never actually vibrates or rings until i turn the screen back on. Then it displays the notification like it was waiting in a queue or something.

How do I get it so that the notification manager will actually alert the user when the screen is turned off?
Update: If I set the timer for 2 minutes, it takes another 2-3 minutes for the notification to actually work. So it does work but it's on a huge delay! Code: So I setup the notification service when the app loses focus, and when the MyCount1 is finished is checks if the app has focus and if not it shows the notification. This all works when the screen backlight is on. Once it goes off it is unreliable.

@Override
public void onWindowFocusChanged(boolean hasFocus){
if(hasFocus == false){
mFocusFlag = false;

ns = Context.NOTIFICATION_SERVICE;
mNotificationManager = (NotificationManager) getSystemService(ns);
icon = R.drawable.statusbar;
tickerText = "Check the timer!!!";......................................