Collision detection failing; Slow framerate caused by non-on-screen shapes about andengine HOT 1 OPEN

Hello .
i have tried to make a simple game of balloon shoot using andengine and in game 
i have fall down baloon successfully but when i have  going to shoot the 
balloon through the another object of bullet then i can shoot only one object 
of balloon which i had taken static ..but i had taken array of balloon and 
falling it using for loop..so in the for loop how can i use the 
"registerUpdateHandler"  
my balloon code is following ..


  for(int i=0;i<10;i++)
                 {
                    pX[i] = random.nextInt(CAMERA_WIDTH-1);
                    pY[i] = 0;
                    balloonArray[i]=new Balloon(pX[i]+20, pY[i], this.mBallTextureRegion);
                     balloonArray[i].setVelocity(i+10, 40+i);
                     scene.getTopLayer().addEntity(balloonArray[i]);

                 }
please give me solution ..