Indeed, applying the pci_fixup_athlon_bug patch you've indicated appears to have solved the problem. Thanks for the pointer, Gabe! Arjan - sorry for misdirecting the original bug report, thanks again for the open source effort! Woohoo! -- Dardo D. Kleiner Connection Machine Facility, Center for Computational Sciences Naval Research Laboratory (Washington, DC) dkleiner@xxxxxxxxxxxxxxxx -- 202.404.7019