Re: DISC AUTHORIZATION FAILURE
Hey im sorry to hear about this happening to you,
please try the follow steps
1.Shut down the computer.
2.Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
3.On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
4.Release all the keys and the power button at the same time.
5.Press the power button to turn on the computer.  
If this does not work please try these steps
Upon hitting the power button to turn the Mac back on you will need to hit the CMD + Option + P + R buttons all at the SAME TIME and wait till you here the Macintosh Chime 3 times. You can let go after the 3rd chime. Log on to your computer and launch the game.
Please Let Me Know If These Steps Works
Best Of Luck To You, Hope This Helps
-Built4Sin187