Today I’ve got a black (sad) screen after restarting the computer. The boot process was fine but everything seems to hang when the nvidia drivers was supposed to kick in and Xorg start.

It was impossible to fall back to any console text login type.

I’ve searched the internet here and there, but I was not able to find any solution or bug report, so I come up with an workaround.

I think the problem is due to the new kernel that I’ve installed following one of the suggested update and the incompatibility with the nvidia drivers. I don’t know if it is the true problem, but I have an hint that this can be true.

As the matter of fact I’ve changed the kernel at the boot time  (Push Esc when GRUB is showing the timeout for the default choice) and I choose the previous version (i.e. Ubuntu 8.10, kernel 2.6.27-12-generic).

With this one I was able to login and my system seems to be completely functional, up and running again.

For the time being I decided to stick with this kernel.  I edited the grub menu list (/boot/grub/menu.lst) changing the default 0 (Ubuntu 8.10, kernel 2.6.27-13-generic) with the second option (Ubuntu 8.10, kernel 2.6.27-12-generic).

Here my current menu.lst


# menu.lst - See: grub(8), info grub, update-grub(8)
# grub-install(8), grub-floppy(8),
# grub-md5-crypt, /usr/share/doc/grub
# and /usr/share/doc/grub-doc/.

## default num
# Set the default entry to the entry number NUM. Numbering starts from 0, and
# the entry number 0 is the default if the command is not used.
#
# You can specify 'saved' instead of a number. In this case, the default entry
# is the entry saved with the command 'savedefault'.
# WARNING: If you are using dmraid do not use 'savedefault' or your
# array will desync and will not let you boot your system.
default 2

## timeout sec
# Set a timeout, in SEC seconds, before automatically booting the default entry
# (normally the first entry defined).
timeout 3

## hiddenmenu
# Hides the menu by default (press ESC to see the menu)
hiddenmenu

# Pretty colours
#color cyan/blue white/blue

...
TRIM
...

## ## End Default Options ##

title Ubuntu 8.10, kernel 2.6.27-13-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-13-generic root=UUID=6e98c429-d480-44bd-a689-83114a227939 ro quiet splash
initrd /boot/initrd.img-2.6.27-13-generic
quiet

title Ubuntu 8.10, kernel 2.6.27-13-generic (recovery mode)
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-13-generic root=UUID=6e98c429-d480-44bd-a689-83114a227939 ro single
initrd /boot/initrd.img-2.6.27-13-generic

title Ubuntu 8.10, kernel 2.6.27-12-generic
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-12-generic root=UUID=6e98c429-d480-44bd-a689-83114a227939 ro quiet splash
initrd /boot/initrd.img-2.6.27-12-generic
quiet

title Ubuntu 8.10, kernel 2.6.27-12-generic (recovery mode)
root (hd0,0)
kernel /boot/vmlinuz-2.6.27-12-generic root=UUID=6e98c429-d480-44bd-a689-83114a227939 ro single
initrd /boot/initrd.img-2.6.27-12-generic

### END DEBIAN AUTOMAGIC KERNELS LIST

Note that default 0 takes always the latest.
HIH.

Update: Found the BUG https://bugs.launchpad.net/ubuntu/+source/linux/+bug/337019/