Update overwrites /etc/default/grub

[Chiel ten Brinke]

Today I ran an apt-get update on Ubuntu 12.04 and I noticed the file
/etc/default/grub was overwritten, so I lost all my tweaks.
This update involved a kernel update, which probably caused this problem.
I noticed that there are other people experiencing the same problem.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: update-manager 1:0.156.14.4
ProcVersionSignature: Ubuntu 3.2.0-24.38-generic-pae 3.2.16
Uname: Linux 3.2.0-24-generic-pae i686
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu7
Architecture: i386
Date: Tue May 22 21:40:57 2012
GsettingsChanges:
 com.ubuntu.update-manager first-run false
 com.ubuntu.update-manager launch-time 1337680225
 com.ubuntu.update-manager window-height 572
 com.ubuntu.update-manager window-width 600
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423)
PackageArchitecture: all
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: update-manager
UpgradeStatus: No upgrade log present (probably fresh install)