Re: Cant get X running on 7-Stable/i386! (with both 162.12 or xf86-nv-2.1.8)
Not sure what the problem could be but there are a few things you can try....
Does your kernel have a "device agp"? Try removing it and use the one build-in the nvidia driver.
Does it work with a GENERIC kernel? Try removing the CPUTYPE in make.conf.
Are you sure the machine locks up? I've had some issues in the past where X would consume 99% cpu and the keyboard/mouse was unresponsive but I could still login using ssh.
As for a black screen, is the monitor setup correctly in xorg.conf?