Have you checked that the LiveDVD was burnt correctly? See Checking the integrity of a Live CD on Windows
if you're using Windows, otherwise see Re: Checking the integrity of a LiveDVD/CD
. That would be the first thing I would check.
If you're sure the ISO file you downloaded is perfect (you did check the md5sum
, right?) then you could try creating a LivePenDrive using UNetbootin
(select 'Diskimage', not 'Distribution'). Generally it is faster and less error-prone to use a LivePenDrive than a LiveCD/DVD.