Please make sure that you have tried all possible combinations of boot parameters, especially "acpi=off" and "ide=nodma". Also try resetting the BIOS to defaults and then turning off plug and play and any power management stuff.
For a question like this if nothing else has worked I would suggest reporting it in as much detail as you already have (more if possible) on Barry's Puppy developer forum at
http://www.puppyos.net/forum/
Cheers,
Mark