Thank to kstevens.
You need to have both of these lines in /etc/default/grub
:
GRUB_DEFAULT=saved GRUB_SAVEDEFAULT=true
Then run sudo update-grub
.
Check the entries in /boot/grub/grub.cfg
and they should look something like:
### BEGIN /etc/grub.d/10_linux ### menuentry 'Ubuntu, with Linux 2.6.32-22-generic' --class ubuntu --class gnu-linux --class gnu --class os { recordfail savedefault insmod ext2 set root='(hd0,5)' search --no-floppy --fs-uuid --set c23bb931-2d60-4f48-9086-c8dbdc7fdca6 linux /boot/vmlinuz-2.6.32-22-generic root=UUID=c23bb931-2d60-4f48-9086-c8dbdc7fdca6 ro splash vga=786 quiet splash initrd /boot/initrd.img-2.6.32-22-generic }
The most important line to note is savedefault
. It indicates that this menu entry will save itself as the default when selected. Verify that this line appears under each menu entry.