Comment 70 for bug 477104

I think I've found a solution for me.

Steps:
1. Completely remove grub, grub2, grub-pc and grub-common packages.
2. Delete all files in the /boot/grub directory
3. Delete packages cache, so they'll be downloaded once more (don't know whether it is necessray)
4. Install grub-pc and grub-common packages only
5. Run update-grub2
6. reboot

So, I don't have installed grub and grub2 packages now and it works!