I am having trouble with CDs on my Mac. I have recently backed up sensitive data to a CD. Now, when I put that CD into my Mac to update the backup, it says the CD is read only. I tried changing permissions from the "get info" section. I tried erasing and repairing the disk with disk utility.... I don't know what to do and this is extremely frustrating. I just want to be able to update my backups on the /writable/ CD.. Thanks for any help/suggestions offered.