I have a cd-r disc that I burned some data on with my pc. My pc crashed on me so I am now using a Powerbook G4 loaned to me from a friend. Everytime I put the disc in I get a popup window that says ' You have inserted a disk containing no volumes that Mac OS X can read. To continue with the disk inserted, click ignore'. Im given the option to click either IGNORE or EJECT. Either one just ejects the disk back out. What can i do and why wont my mac read the disc?