i had a similar problem but it wasnt related to the usb port as yours seems to be, lfs would randomly crash, screen frozen, sound looping and after a minute or so monitor would power off and after another minute and alot of 3 finger saluts a bsod would appear pointing to the nvidia drivers. now the nvidia drivers dont solve nothing, i tried all sorts of drivers. what i see here is that you have the same chipset manufacturer as me, SIS, which in my opinion is crap, no matter what chip nº it is.
i found that with hvs off in lfs i could play fine but with huge fps loss wich is no option.
for me the write combine box in windows display properties did it. this is supposed to speed up the pci or agp transfers(i dunno how). with the box checked i can play every game without any problem EXCEPT LFS, if i wanna play lfs i remove the check, reboot and there i go. there is a fps loss with the option off but i guess ill have to live with it until i get a decent mobo.