On 1.3 ISO, just as the installer is running Anaconda to select the packages, it coughs up a hairball, "An error occurred unmounting the CD. Please make sure you're not accessing /mnt/source from the shell on tty2 and then click OK to retry." Nothing I do will allow me to continue or go back. I have to reboot, and the same error comes up. The CD checks out good, and the checksum is right. Any thoughts?