I've been bitten by this. There's already a bug report:
More specifically in my case it was the update to grub-pc. I don't actually have grub2 installed. It seems to be a meta-package. I haven't needed it anyway.
Code:paul@lubuntu-64:~$ aptitude show grub2 Package: grub2 New: yes State: not installed Multi-Arch: foreign Version: 2.00-18ubuntu2 Priority: extra Section: universe/admin Maintainer: Ubuntu Developers <firstname.lastname@example.org> Architecture: amd64 Uncompressed Size: 32.8 k Depends: grub-pc (= 2.00-18ubuntu2), grub-common Conflicts: grub2 Provides: grub2 Provided by: grub2 Description: GRand Unified Bootloader, version 2 (dummy package) This is a dummy transitional package to handle GRUB 2 upgrades. It can be safely removed. Homepage: http://www.gnu.org/software/grub/ paul@lubuntu-64:~$