I was impatient to test if kernel without smp was ok, but I got the same experience.
Before, I didn't tell you that I get the black screen, using nvidia, always after starting x manually. I use runlevel 3.
With the new kernel 2.6.8-without-smp, I first tried startx and X server crashed, with the "no screen" message in /var/log/XFree86.0.log:
(EE) NVIDIA(0): Failed to initialize the NVIDIA kernel module!
(EE) NVIDIA(0): *** Aborting ***
(II) UnloadModule: "nvidia"
(II) UnloadModule: "vgahw"
(II) Unloading /usr/X11R6/lib/modules/libvgahw.a
(EE) Screen(s) found, but none have a usable configuration.
Fatal server error:
no screens found
Then I installed the 6111 patched driver, but I get the same problem that the one with kernel with smp. Same warnings, but no error message.
I also tried to load nvidia module during boot process, even though the problem might not be exactly the same that Giblet was telling about.
Problem may not be caused by smp.
Can something be deduced ?