sudden loss of puppy with Bad EIP value

[zipt]

Things had been going well, enjoying 2.12 and succeeding with wireless access on my ThinkPad 600E. Made a change to modprobe.conf and at next boot, puppy fails with a message of "Code:Bad EIP value" plus a lot of register values. Now the same happens at each attempt to boot though I imagine modprobe isn't the problem as it's a fresh live-CD start each time.

I re-wrote the CD - no change. I upgraded to the latest BIOS - no change. I trawled the net for help but nothing obvious to try. Then thought I'd ask here, with fingers crossed.

I also tried a number of other distros with the following results:

puppy: After "Setting up network interfaces", the failure occurs with the Bad EIP message.

puppy pfix=rdsh: that gets me a # prompt OK.

puppy ide=nodma: gives Bad EIP value.

ubuntu 6.10: gives "Invalid compressed format (err=2) Kernel panic - not syncing: VFS:Unable to mount root fs on unknown-block(1,0)"

DSL 2.3: works fine!!

Knoppix 5.01: gives
"Scanningfor USB/Firewire devices... Done
Enabling DMA acceleration for: hda [disc details...]
Enabling DMA acceleration for: hdc [DVD-ROM details]
Looking for CD in: /dev/hda" then it hangs.

knoppix nodma: works fine!!!

Ok. I'm stumped. Any comments welcomed.
Thanks,
zipt