X and G4 dual processor with nVidia

[Lucio <lcml@pixel.it>]

I've a problem with X on my Mac (G4 dual processor with nVidia graphics card): 
when I startx I get a black screen on the virtual console #7, and no errors 
on the virtual console #1, so I assume X believes to be ok. I can kill X from 
another virtual console and it exits like usual ("Waiting for X server to 
shut down...").
I've already tried several combinations of the options in "dpkg-reconfigure 
xserver-xfree86" (nv driver, several different resolutions and color depths), 
all of them leading to the same behavior. It doesn't seem to be monitor 
related, because it's the same with all the resolutions from 1600x1200 down 
to 640x480. The problem shows both in Woody and Sarge (Sarge has the 2.6.7-1 
kernel). I've already specified the correct BusID (lspci tells 00:10.0, I 
used PCI:00:16:00).

Is there anything else I should try to get it working?

Lucio.