Originally Posted by netllama
What kind of Dell system is this?
It is a Precision 470.
If you specify a default depth in your xorg.conf, does that have any impact?
No, it has no effect.
In the mean time, it seems that this problem was noticed last year, and there's a workaround:
So I've put the kernel patch back, and now Xorg starts again with the nvidia driver. However it still only gives me 8bpp even with DefaultDepth set to 24.