HELP! can't mmap package info file `/var/lib/dpkg/available'

I am trying to remaster a KnoppixSTD CD. (Their forum doesnt have much activity so I am posting here). I have installed to the hard drive and have copied the CDs file system to the drive. I chroot to that directory and try to update my packages.
No matter what I have tried, including googling for answers, I can not find anything that fixes my problem. Most posts say to remove and recreate the available file and toggle back and forth between apt-get clean and apt-get update/apt-get dist-upgrade. I cannot even apt-get install apt or apt-get install debconf. Even when I try to use dselect or dpkg I get errors.

HELP!!!!!!