I've had the system running a cooker test install that Mandrake released for ~18 hours now. It's kernel 2.6.0 based, and with APIC enabled in bios but disabled in kernel parameters ('nolapic noapic') it seems to be ok.
I asked around on IRC about the sound issue, and someone suggested turning the mixer settings down a bit... I set everything to about 80%, and the static is at least much lower, if not gone.
Thanks for the wiring tips, I'll have to dig around inside my computer a bit to see if I do have some wires going where they shouldn't.