Pushed all the sliders, Number of Explosions, Particles in explosions, Velocity of particles, and Particle fade all the way to the right and I still didn't get multiple explosions.
I decided to push the speed value to maximum and then it started to give me multiple explosions. If you move the speed control down even one notch the rapid multiple explosions slow down tremendously.
Also does the 'Face out' on an effect supposed to turn all the pixels off by then end of the effect. I applied the fade out at the end of my presentation and there remains a number of pixels left on very dimly and the twinkle never fades out.