Your not having the usual install problem. Most install problems come from just getting the CD to boot. Those are usually fixed by using a cheat code at boot.
But your getting into the middle of the install process. Thats almost always a sign of a bad burn. But don't think that your problem since you verified the CD. Now I wonder about the CD player itself. It may have a bad spot somewhere.
Try doing a net install using the https://help.ubuntu.com/community/Installation/MinimalCD. The iso is only a 9-10 MB download and gets what is needed from the Internet
Or try installing from a USB Stick.