Science Buddies: "Ask an Expert"

My Science project is due this Monday and I am confused on a few parts. Whenever i shine the beam down i get the same angles for the CD and then i get the same for the DVD every trial. I always only get two reflecting though and I'm not sure which they are. Is there any variation i can do on the project without the math problem beacause that's the only way i might be able to finish in time. Am i performing the experiment correctly?

If you change the incident angle, the angles of the refracted beams should change. If not, there is something wrong.