Obteve o mesmo erro
(Lendo banco de dados ... 110573 arquivos e diretórios atualmente instalados.)
Preparando para substituir linux-image-2.6.22-14-generic 2.6.22-14.51 (usando linux-image-2.6.22-14-generic_2.6.22-14.51_amd64.deb) ...
Done.
Descompactando substituto linux-image-2.6.22-14-generic ...
Running postrm hook script /sbin/update-grub.
Searching for GRUB installation directory ... found: /boot/grub
Searching for default file ... found: /boot/grub/default
Testing for an existing GRUB menu.lst file ... found: /boot/grub/menu.lst
Searching for splash image ... none found, skipping ...
Found kernel: /boot/vmlinuz-2.6.22-14-generic
Found kernel: /boot/memtest86+.bin
Updating /boot/grub/menu.lst ... done
Instalando linux-image-2.6.22-14-generic (2.6.22-14.51) ...
Running depmod.
update-initramfs: Generating /boot/initrd.img-2.6.22-14-generic
/usr/sbin/mkinitramfs: 13: getopt: not found
Terminating...
update-initramfs: failed for /boot/initrd.img-2.6.22-14-generic
Failed to create initrd image.
dpkg: erro processando linux-image-2.6.22-14-generic (--install):
subprocesso post-installation script retornou código de saída de error 2
Erros foram encontrados durante processamento de:
linux-image-2.6.22-14-generic
eh isso que aconteceu olha ai....