Hi

In case it's useful, lots of weird stuff happens when I boot with 
pci=noacpi (see attachment),none of which results in a successful boot :(

I particularly liked this bit...

PCI: Probing PCI hardware
PCI: Discovered peer bus 0e
PCI: Discovered peer bus 12
PCI: Discovered primary peer bus 04 [IRQ]
PCI: Discovered primary peer bus 13 [IRQ]
PCI: Using IRQ router ServerWorks [1166/0201] at 00:0f.0
PCI BIOS passed nonexistent PCI bus 0!
PCI BIOS passed nonexistent PCI bus 0!
PCI BIOS passed nonexistent PCI bus 14!
PCI BIOS passed nonexistent PCI bus 14!
PCI BIOS passed nonexistent PCI bus 18!

;)