Is this problem (the whole system freezes with a message says you must manually power off the computer and reboot) the same as the "Lan-Freeze issue" mentioned in http://osx86.wikidot.com/known-issues ??

I suppose the first solution using the cpus=1 option is for dual-core cpus? My AMD cpu has only one core. I don't know if this would help or not. Will give it a try.

The second solution as lanxxx said is not to use the onboard nforce lan port. I guess I can get a stand alone ethernet card (Marvell Yukon or realtek 8169) and give this a try, or according to other posts I can find, just use wireless.