I am finding that my dvd drive is inconsistent in reading and mounting dvds. I just bought several movies and I wanted to rip a backup copy of each. My drive will open and mount some of the movies but not others. Any suggestions?
It could just be getting old. DVD drives do fail over time. Check to see that it isn't loaded with dust. Try blowing it out with compressed air and see of that helps.
If you do decide to get a new one, it may be hard to find because the 2008 Mac Pro uses IDE/ATAPI connectors and not SATA connectors so you need to find an older designed drive that supports IDE/ATAPI connections.