Can't find knoppix filesystem, sorry.

[Harry Kuhman]

I changed the CD rom for a new one and had no problem booting from CD.

Yup, this confirms that the problem was due to a marginal burn, marginal or dirty optics in the old drive, or an old drive that needed a cheat code. All very common problems but the first two few will accept the answer to unless thay discover it themselves.

Now I have a new question.

Then you would be better served by starting a new thread than by appending it here. Or better yet, use the forum search feature, you are not the first to ask this.