I'm a bit stumped, but if you think it might be acpi - you can turn it off from lilo.
The link is obviously not a direct solution, but shows you where to add `append "acpi=off"` to your lilo.conf. Presumably this can also be added at the lilo prompt, too.
Have you tried checking you bios? Tinkering with stuff in there can sometimes help - also check your RAM with memcheck or similar, see if that helps.
What was the difference between the other distros and Vector/Slack? I know SuSE uses grub - might be as simple as the configuration of lilo is not optimal.
Sorry I couldn't be more help - good luck,