package gcj-4.5-jre-headless 4.5.2-8ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2

[paul]

paul@pdk-hp2:~$ sudo apt-get purge gcj-jre
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
  gcj-jre*
0 upgraded, 0 newly installed, 1 to remove and 0 not upgraded.
6 not fully installed or removed.
After this operation, 20.5 kB disk space will be freed.
Do you want to continue [Y/n]?
Setting up openjdk-6-jre-headless (6b22-1.10.4-0ubuntu1~11.04.2) ...
update-alternatives: error: /var/lib/dpkg/alternatives/keytool corrupt: line not terminated while trying to read status
dpkg: error processing openjdk-6-jre-headless (--configure):
 subprocess installed post-installation script returned error exit status 2
dpkg: dependency problems prevent configuration of openjdk-6-jre:
 openjdk-6-jre depends on openjdk-6-jre-headless (>= 6b22-1.10.4-0ubuntu1~11.04.2); however:
  Package openjdk-6-jre-headless is not configured yet.
dpkg: error processing openjdk-6-jre (--configure):
 dependency problems - leaving unconfigured
Setting up gcj-4.5-jre-headless (4.5.2-8ubuntu1) ...
No apport report written because the error message indicates its a followup error from a previous failure.
                                                                                                          update-alternatives: error: /var/lib/dpkg/alternatives/keytool corrupt: line not terminated while trying to read status
dpkg: error processing gcj-4.5-jre-headless (--configure):
 subprocess installed post-installation script returned error exit status 2
dpkg: dependency problems prevent configuration of gcj-4.5-jre:
 gcj-4.5-jre depends on gcj-4.5-jre-headless (= 4.5.2-8ubuntu1); however:
  Package gcj-4.5-jre-headless is not configured yet.
dpkg: error processing gcj-4.5-jre (--configure):
 dependency problems - leaving unconfigured
No apport report written because MaxReports is reached already
                                                              Errors were encountered while processing:
 openjdk-6-jre-headless
 openjdk-6-jre
 gcj-4.5-jre-headless
 gcj-4.5-jre
E: Sub-process /usr/bin/dpkg returned an error code (1)

ProblemType: Package
DistroRelease: Ubuntu 11.04
Package: gcj-4.5-jre-headless 4.5.2-8ubuntu1
ProcVersionSignature: Ubuntu 2.6.38-13.54-generic 2.6.38.8
Uname: Linux 2.6.38-13-generic x86_64
NonfreeKernelModules: fglrx
Architecture: amd64
Date: Thu Jan 26 05:09:09 2012
DpkgTerminalLog:
 Setting up gcj-4.5-jre-headless (4.5.2-8ubuntu1) ...
 update-alternatives: error: /var/lib/dpkg/alternatives/keytool corrupt: line not terminated while trying to read status
 dpkg: error processing gcj-4.5-jre-headless (--configure):
  subprocess installed post-installation script returned error exit status 2
ErrorMessage: subprocess installed post-installation script returned error exit status 2
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
SourcePackage: gcj-4.5
Title: package gcj-4.5-jre-headless 4.5.2-8ubuntu1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2
UpgradeStatus: No upgrade log present (probably fresh install)