I upgraded to 12.10 (32-bit) a few weeks ago (from 12.04) and everything has been running fine. A few days ago, the updater installed the latest kernel (18.104.22.168 ?) and since then I always have to manually select the latest kernel when booting.
I tried looking for /etc/default/grub but that file didn't exist. I installed Grub Customiser but that, apart from taking minutes to appear, suggested that the default kernel was '0'. But it did create a small /etc/default/grub file with the following entries:
GRUB_DEFAULT="0" GRUB_TIMEOUT=10 GRUB_SAVEDEFAULT="false" #UNNAMED_OPTION=""
I have run
sudo update-grub and have also tried changing the default from "0" to 0 but grub insists on defaulting to the previous kernel.
uname -a in the manually-selected latest kernel gives:
Linux typhoon 3.5.0-22-generic #34-Ubuntu SMP Tue Jan 8 21:41:11 UTC 2013 i686 i686 i686 GNU/Linux
Letting the boot timeout and select the default kernel results in:
Linux typhoon 3.5.0-21-generic #32-Ubuntu SMP Tue Dec 11 18:52:46 UTC 2012 i686 i686 i686 GNU/Linux
The boot menu looks like this:
My machine has 2 hard disks. The main disk is dual-boot with 12.10 (default) and winXP.
The 2nd disk is purely for data and isn't mounted automatically i.e. selecting it in nautilus always mounts it before displaying anything. It is available to both operating systems and is formatted as NTFS.
fdisk -l results in:
sda1 is the WinXP partition.