xchm install on knoppix persistent image

Hi....

I have made a persistent image of knoppix on my harddisk. I opened terminal and changed as superuser(su) and typed apt-get update.... It was taking a longtime and my net connection is limited. In the night i can download unlimited amount. So i halted the process using ctrl + c. When i tried the same command at the night i got errors...

To install xchm i typed apt-get install xchm. It downloaded the files but cannot install. I was getting errors

/usr/sbin/dpkg-preconfigure --apt
segmentation fault

Plz help..