install sun-java6-jdk on lucid x64

I tried the standard repo/method:

sudo add-apt-repository "deb http://archive.canonical.com/ lucid partner"
sudo apt-get update
sudo apt-get install sun-java6-jdk

which did work for me on my laptop. But I couldn't get this to work, for the life of me, on my lucid x64 server, for weird reasons:

Package sun-java6-jre is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package sun-java6-jre has no installation candidate

I had to resort to a custom ppa for sun-java6-jdk that worked just fine
https://launchpad.net/~ferramroberto/+archive/java

source: http://ubuntuguide.net/install-sun-java-6-jrejdk-from-ppa-in-ubuntu-11-04