Linux System Freeze
I was having a lot of lockups with Ubuntu Gutsy when I had it loaded on my Asus moboard that had the Nvidia i650 chipset. I swapped that moboard with a MSI D965 chipset and haven't had any problems, which leads me to believe that the Gutsy kernel didn't like something about nvidia. I had no problems running Feisty on that nvidia chipset. One thing I never did was try to build a new kernel with Gutsy. Maybe I should have. I haven't loaded any linux platform with an AMD cpu, only Intel.
I know that probably isn't much help, but maybe something to look at.