CD Boot works, HDD Installed boot fails at second hurdle

I'm trying to get Knoppix to boot after being installed onto the hard disk in a Rock Sigma (laptop/notebook).

When booting Knoppix from the CD everything works, apart from the Knoppix pre-boot graphic is corrupt, which I figure is unimportant.

I partition the HDD half a gig of swap, the rest ext3 and do appropriate mkfs etc.

I have used the knoppix-installer script to install both Knoppix style and traditional Debian systems, however I always get the same problem when
I try to boot into knoppix from the HDD.

The Dedian graphic come up with a list of three kernels to boot, linux, linux2.4 and linux2.6 they all fail in different ways.

linux2.6 loads the kernel then the laptop reboots.
linux2.4 loads the kernel then stops after grawing some colourful gibberish on the screen.

It looks to me like the miniroot load isn't even being attempted.

I've tried assorted nodma etc. but no luck.

What options does the knoppix CD kernel use, and what is the difference between CD and HDD boot.

TIA

Bri