I found out, that the Ultra66 controller shared IRQ 9 with the SBLive, Ethernet etc. The problem (yes, I am a newbie) is that I can't seem to change the IRQ's.
When assigning them each an available IRQ in the BIOS, they are all restored when entering W2K. And in the device manager, the "setting based on" and "use automatic settings" are ghosticons...
I guess that it has something to do with turning off the ACPI and forcing the new IRQ's to be accepted? But how...