The Ubuntu Live CD is asking for a password after booting in GDM. The username "ubuntu" and an empty password don't work. Normally the same CD never asked for a password. What is happening? What is the correct password? I badly need the live system!
Edit: none of the proposals at https://answers.launchpad.net/ubuntu/+question/9193 worked.
Sounds as if the CD is damaged, check the CD for scratches or dirt and then check the integrity of the CD.