Comment 2 for bug 474917

I got bitten by this upgrading 9.04->9.10 too

after the upgrade the box booted into 2.6.31 and gdm failed to start and the console just flashed

# uname -a
Linux nyx 2.6.31-14-generic #48-Ubuntu SMP Fri Oct 16 14:05:01 UTC 2009 x86_64 GNU/Linux

the doc, /usr/share/doc/nvidia-185-kernel-source/README.Debian, looks to be quite out of date
I tried 'm-a a-i nvidia-kernel-source' but that complained about nvidia-kernel-source being a virtual package with no installation candidate.
I ended up running 'make ; make install' just to get the box working again

a bit of searching and I discovered mention of dkms (not mentioned in the README.Debian)

# dkms status
nvidia, 185.18.36, 2.6.28-11-generic, x86_64: installed

I noticed dkms was in /var/lib/dpkg/info/nvidia-185-kernel-source.postinst so I ran

# dpkg-reconfigure nvidia-185-kernel-source
Removing all DKMS Modules
Done.
Loading new nvidia-185.18.36 DKMS files...
Building for architecture x86_64
Building initial module for 2.6.31-14-generic
Done.

nvidia.ko:
Running module version sanity check.
 - Original module
 - Installation
   - Installing to /lib/modules/2.6.31-14-generic/updates/dkms/

depmod....

DKMS: install Completed.

# dkms status
nvidia, 185.18.36, 2.6.31-14-generic, x86_64: installed

now it works

I don't see how this was going to work during an upgrade that included installing a new kernel