dpkg-reconfigure in postinst fails on 1.6.7

[Neil Wilson]

I have a package with a postinst containing:

# Update the console to a GB keyboard and the default fonts for that
# keyboard within the release.
setup_console() {
  echo "Fixing console settings"
  rm -f /etc/default/keyboard
  rm -f /etc/default/console-setup
  debconf-set-selections <<EOF
keyboard-configuration keyboard-configuration/modelcode string pc105
keyboard-configuration keyboard-configuration/layoutcode string gb
EOF
  dpkg-reconfigure --frontend=noninteractive -u keyboard-configuration
  dpkg-reconfigure --frontend=noninteractive -u console-setup
}

that has been working fine on all releases of Ubuntu up to Quantal with v1.16.4.3ubuntu1 of dpkg. However the latest 1.6.7 dpkg appears to have stopped this working:

Fixing console settings^M
update-initramfs: deferring update (trigger activated)^M
dpkg: error: dpkg status database is locked by another process^M
dpkg: error processing cloud-build (--configure):^M
 subprocess installed post-installation script returned error exit status 2^M

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: dpkg 1.16.7ubuntu2
ProcVersionSignature: Ubuntu 3.5.0-3.3-generic 3.5.0-rc5
Uname: Linux 3.5.0-3-generic i686
ApportVersion: 2.3-0ubuntu2
Architecture: i386
Date: Tue Jul 10 08:33:23 2012
SourcePackage: dpkg
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[dino99 (9d9)]

This is no more a supported version now