How did you prohibit XP to install an ACPI system?
AFAIK (and that's not soooo much ;)) there are 2 things to do: 1. Select "Standard PC HAL" during install and 2. select something like "PnP BIOS installed: No" in the BIOS. Sounds like your MoBo wanted to behave first but was persuaded later by XP's PnP mechanisms to do not. I'm not sure if this is possible at all on your machine and which of the both steps it's related to, but is IRQ sharing active? It shouldn't.
is it possible that the bios (if that may be the problem) wouldn't be able to hold winxp upright?
Yes, but I'm writing this on an even older and smaller machine (AMD K6-2/550MHz, 392MB RAM) and XP runs (much!) better than I thought. XP installed itself with the "Standard PC" HAL and "NT-APM Legacy Support" without needing my attention. When I select to display hidden devices in Device Manager, I can see that the "NT-APM Legacy Interface Node" is disabled for some unknown reason. Sorry, I'm afraid I can't help you much with this but maybe you found a suggestion in my jabbering. :mrgreen: