Cdr file hangs system up on a black screen
I am using an older (6 years) Total Training DVD set. To save wear and tear on my DVD drive, because of the constant starts and stops, I imported it as a disc image to operate from my hard drive. However, it hangs the system up on a black screen. It plays the first note of music in the menu, and then the cursor shows and moves, but the rest of the system is locked up. I've had to hard reboot five times. This also happened on an earlier DVD from the same set yesterday. The DVD plays fine.
Is this indicative of copy protection or an issue in my system? I'm running an older (about 2008) Macbook with OSX Leopard.
Thanks