This problem has been discussed in many forums. I hope this helps solve it. It works for me on a Toshiba Satellite S1800-614.

The problem:
Knoppix 3.3 on many Toshiba laptops hangs at the hard disk detection.
Starting Knoppix with the dma option will make it go past this first stumbling block, however the disk partition will still not be recognised.
Running cat /proc/partitions will confirm:
major minor #blocks name
3 0 19535040 hda
I.e., no partitions recognised

Solution:
From a shell run:
sudo hdparm -z /dev/hda
Now cat /proc/partitions should return all the correct partitions, e.g.:
major minor #blocks name
3 0 19535040 hda
3 1 11269566 hda1
3 2 6345675 hda2
3 3 1429785 hda3
3 4 1 hda4
3 5 489951 hda5
and you can progress to a hard disk installation or whatever you want to do.

Something strange:
I still have a doubt. If I run "sudo hdparm /dev/hda" I get:
/dev/hda:
multcount = 16 (on)
I/O support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 1 (on)
keepsettings = 0 (off)
nowerr = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 2432/255/63, sectors = 39070080, start = 0
This output is the same before and after running hdparm with the -z option.
What is missing is a line like:
busstate = 1 (on)
which would normally appear using Knoppix 3.2. Strange!

More strange stuff:
If I don't use the "knoppix dma" option to boot, I'm pretty sure I get different behaviours depending on the content of the partition table. Sometimes Knoppix hangs, sometimes it returns "interrupt lost" errors. I've done lots of experimentation with partitions sizes and types (for reasons not related to the problem I'm describing) and it does seem to make a difference, especially swap partitions.
I think this is relevant but I don't know how. I may try to recreate a certain configuration and describe the results if you think it's important.

Other options tried:
Just for information, I've tried "failsafe", most of the "no-" and "irq" options. None of them works.

The way forward:
I have almost 10 years of unix experience as user/administrator but I'm relatively new to knoppix. I understand the problem could be with the knoppix HW detection script or with the kernel, but that's just what I gather from other postings.
I'm happy to progress the bug report and be a tester, but please give me some pointers on who I should be progressing this with. Thank you.

Regards