i'm comparing the dmesg output from a system running 3.99.8 on "the same" mobo 
to this one.

The 3.99.8 system knows the names of the chipsets, but the daily build iso 
doesn't - even though the chipsets seem to be the same codes.

I see that the ohci0 interrupt pins are different, though the irqs are the same. 
Probably doesn't matter.

The ide lines are different:

working system:

viaide0 at pci0 dev 6 function 0
viaide0: NVIDIA nForce4 IDE Controller (rev. 0xf2)
viaide0: bus-master DMA support present
viaide0: primary channel configured to compatibility mode
viaide0: primary channel interrupting at ioapic0 pin 14 (irq 14)
atabus0 at viaide0 channel 0
viaide0: secondary channel configured to compatibility mode
viaide0: secondary channel interrupting at ioapic0 pin 15 (irq 15)
atabus1 at viaide0 channel 1

non-working system

viaide0 at pci0 dev 6 function 0
viaide0: NVIDIA nForce4 IDE Controller (rev. 0xf2)
viaide0: bus-master DMA support present
viaide0: primary channel configured to compatibility mode
isa_intr_establish: no MP mapping found
viaide0: primary channel interrupting at irq 14
atabus0 at viaide0 channel 0
viaide0: secondary channel configured to compatibility mode
isa_intr_establish: no MP mapping found
viaide0: secondary channel interrupting at irq 15
atabus1 at viaide0 channel 1

and so on.

The chipset revs all seem to be the same...