Have you tried to copy the DVD? It could be that when the DVD was created, it had an error that wasn't detected.
i have a dell inspiron 15 r laptop.it came with installed windows 8.i wanted to install ubuntu besides windows 8.for this, i firstly partiioned the hard disk into 3 parts.1 is for windows 8, 1 is for ubuntu 1 is for my important files.
everything is ok untill here.but when i tried to boot the laptop from DVD Rom it says "mediatest failure check cable". i am sure that this is not a hardware problem.because my dvd rom works good with windows 8.
moreover it also says same thing while trying to boot from hard disk.what can be the problem?thanks.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic