boots with nohwsetup, hangs with nousb no[everything]

Hi,

I'd really need to know what the difference is, between :
knoppix noapic noagp noapm nodma nomce nofirewire nopcmcia noscsi noswap nousb nosmp noaudio nofstab acpi=off
and :
knoppix nohwsetup OR knoppix -b

because the second ones do boot, whereas the first desperately hangs, printing some seemingly irrelevant details :
MODPROBE: MODPROBE : CAN'T LOCATE MODULE CHAR-MAJOR-4
MODPROBE: MODPROBE : CAN'T LOCATE MODULE CHAR-MAJOR-4(has to do with virtual consoles)
MODPROBE: MODPROBE : CAN'T LOCATE MODULE BLOCK-MAJOR-2
MODPROBE: MODPROBE : CAN'T LOCATE MODULE BLOCK-MAJOR-2(has to do with floppy, and I have none).

Here are some details :
1- I've been trying to fix a G4 Titanium that cannot boot OS 9.1 (the only hard-drive installed os) any more [problem was : it managed to go through several starting screen, performed some successful checks and verifications for brutal poweroff, but froze at the last one (starting OS 9.1) ; I tried both starting with no extensions and zapping the pram, to no avail)

2- Tried starting in firewire target mode ; I get the firewire icon on the screen but the G4 is undetectable on the other computer I connect it to.

3- Tried various liveCD :
-knx (linuxtag ppc port of knoppix) freezes after "autoconfiguring devices", printing two seemingly irrelevant errors :
MODPROBE: MODPROBE : CAN'T LOCATE MODULE CHAR-MAJOR-4
MODPROBE: MODPROBE : CAN'T LOCATE MODULE CHAR-MAJOR-4(has to do with virtual consoles)
MODPROBE: MODPROBE : CAN'T LOCATE MODULE BLOCK-MAJOR-2
MODPROBE: MODPROBE : CAN'T LOCATE MODULE BLOCK-MAJOR-2(has to do with floppy, and I have none).
Putting all those cheatcodes together : noapic noagp noapm nodma nomce nofirewire nopcmcia noscsi noswap nousb nosmp noaudio acpi=off nofstab
I still get the error.

But if I start with : nohwsetup, or -b, it boots successfully. But I get again a freeze of the system and the two modprobe errors if I try to run kudzu once the system has booted.
-Knoppix MiB freezes after "USB found, managed by hotplug". No cheatcode will get it to boot successfully.
-Gentoo freezes after a line that states approximately "coldplugging firewire" (and no ok appears)
But booting is successful with : nodetect
-Ubuntu freezes after this line :
ohci 1394 : "Unexpected PCI resource length of 1000!". No cheatcode works.


So if someone has any idea what's wrong with my computer... I think it's something with firewire or PCI management, but I don't know much about hardware. I hope the answer might lie in the difference between booting nohwsetup and booting no[everything]...

Thanks very much for any help.