java alternative link broken after upgrade

After recent upgrade to precise, I find that java programs are broken. Further investigation shows:

$ update-alternatives --display java
update-alternatives: warning: alternative /usr/lib/jvm/java-6-openjdk/jre/bin/java (part of link group java) doesn't exist. Removing from list of alternatives.
java - auto mode
  link currently points to /usr/lib/jvm/java-6-openjdk/jre/bin/java
No versions available.

$ dpkg -L openjdk-6-jre-headless | grep bin/java
/usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java
/usr/lib/jvm/java-6-openjdk-amd64/bin/java-rmi.cgi
/usr/lib/jvm/java-6-openjdk-amd64/bin/java

It seems that openjdk-6-jre-headless now has a 'amd64' in its path that wasn't there before. This was not accounted for on upgrade and my /usr/bin/java link is broken.

An attempt to fix with update-java-alternatives failed, and made me worse off, I now have no /usr/bin/java link.
 $ sudo update-java-alternatives --set java-1.6.0-openjdk-amd64
 update-alternatives: error: no alternatives for appletviewer.
 update-alternatives: error: no alternatives for apt.
 update-alternatives: error: no alternatives for extcheck.
...
  update-java-alternatives: jdk alternative does not exist: /usr/lib/jvm/java-6-openjdk-amd64/bin/xjc
update-alternatives: error: no alternatives for policytool.
update-java-alternatives: plugin alternative does not exist: /usr/lib/jvm/java-6-openjdk-amd64/jre/lib/amd64/IcedTeaPlugin.so

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: openjdk-6-jre-headless 6b23~pre11-1ubuntu2
ProcVersionSignature: Ubuntu 3.1.0-2.3-generic 3.1.0
Uname: Linux 3.1.0-2-generic x86_64
ApportVersion: 1.25-0ubuntu1
Architecture: amd64
Date: Wed Nov 9 09:46:46 2011
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: openjdk-6
UpgradeStatus: Upgraded to precise on 2011-11-07 (2 days ago)