Now after remowing my Intel PRO1000MT server network card from PCI-X slot 6, i can boot without any problems :)
..the PCI-X should also work. I think it may be good to investigate why it gets such a high bus number.
The K8 code assigns bus numbers that way. The primary southbridge link gets bus 0x0, the next HT link gets 0x40... That's just the way it was written.
Thanks, Myles