After Effects: Lights and Cameras

Im pretty confident about using after effects. In a lesson last meek were were asked to experiment with cameras and light in After Effects CS5. I created this using an image of earth, and image of the moon, a lens flair effect, the particle playground plugin for the stars in the background and two lights (one behind the earth and one behind the came illuminating the moon) and manipulating them all in 3D space. This is the end result. The only problem is the earths seems to flicker. I never notices until I uploaded (I know) but its must have been the way I keyframes the lights. Another lesson learnt.