For what it's worth, I just got nvidia drivers working on my testing box
(+Nvidia 7600) by picking up linux-image-2.6.22-2-k7 from sid, and
module-assistant building nvidia (so also need nvidia-kernel-common and
nvidia-kernel-source from sid, and then nvidia-glx too once the
modass-build is installed. Fairly painless (and I normally avoid sid
packages at all costs).
[So now I've got compiz! Fun! But be sure to read the bugs re needing
to install some plugins else it effectively just nukes your window
manager.]
Tim