yeah, of course i have these stupid errors too.. I have an nforce 4 as well, but as mentioned, i got rid of it in the bios. I'd be surprised if leopard was still bugging because of something which was removed altogether from the bios. I am using the ip over firewire thing right now, and at least i don't have random freezes.
Damn, i just wish i had a mac pro, life would be simpler..
thanks for your help in any case, and no worries about the messages - the whisper function is just not very well designed..