cannot go back from nouveau to nv

[Fumiaki Okushi <fumiaki@okushi.com>]

Hi,

I'm running Debian Squeeze amd64.
I'm trying to go back to using nv after trying to get nouveau working 
and failed.

I purged the two packages I had to install to attempt nouveau:
- xserver-xorg-video-nouveau
- libdrm-nouveau1
and restored /etc/X11/xorg.conf to the one I was using with nv.

(Special note: xorg.conf is needed on my PC because the driver cannot 
obtain the correct info to auto configure.)

I rebooted, but X won't work.
Near the end of Xorg.0.log has the following message:

(EE) NV: Kernel modesetting driver in use, refusing to load

Indeed, nouveau.ko and its dependent drivers (eg., drm_kms_heler.ko) are 
still getting loaded.

What do I need to do to go back to using nv?

Thanks,
Fumi Okushi