Myst 3 cd question PLEASE

[SuperD]

I am having a problem, can someone tell me if it is a cd ##### problem. I have gotten to the top of the first world where that freak takes the book and disappears. I push the ball and the 3 windows open, and that bearded guy starts telling me about the 3 worlds. Then all of a sudden my game stops an goes back to windows. Is this a cd ##### problem????? Someone help me please!