Comment 119 for bug 1289977

Problem solved
The problem lied in somehow incomplete grub upgrade. The solution is quite simple:
1) Boot some live CD and chroot to the damaged instalation, like http://ubuntuforums.org/showthread.php?t=1156240
2) Purge all grub* packages
3) Check /boot directory and remove grub and grub2 folders completely
4) Install grub-pc and depending packages
5) Exit chrooted enviroment and reboot