knoppix26 INIT hangs, hda=ide-cd halts, 2.4.27 ok

boot: knoppix26
pauses indefinitely at: Starting init process.INIT: version 2.78-knoppix booting
on a desktop Dell NTFS Win XP PC here, bought new last December.

I get the "(very limited)" cat/ mount/ mod shell only from the bootline: knoppix26 hda=ide-cd. Bootlines that hang include: knoppix26, knoppix26 noscsi, knoppix26 nodma, knoppix26 hda=ide-scsi. I burned iso of Knoppix 3.7, checked the md5sum, "verified" the CD-R, twice. The default empty Knoppix 2.7 bootline boots 2.4.27 no worries, except the HDD is not found. I have run boot: memtest thru Test % reaching 100 and starting over.

Please advise how I could investigate this further.

Ah.
boot: knoppix26 noagp noaudio noapm noapic acpi=off nodma nopcmcia noscsi nousb
worked once. I'll now retry and binary search. I built that bootline by guessing I could knoppix26 for knoppix after a Google search of knoppix failsafe gave me
http://www.knoppix.nl/3.7/knoppix-cheatcodes.txt

boot: knoppix26 acpi=off

works. Thus I now have a working Knoppix 3.7 boot line, so I'm done here ... unless you think I can help discover why acpi=off is needed here.