Comment 4 for bug 157721

It's true, sun-java6-plugin is only available for 32 bit, but icedtea-java7 provides a browser plugin for 64bit, so it should basically work, but there are still some compatibly problems.

You can't get a browser, which is compiled for 64bit, to run in 32bit mode. You can either download a 32bit-version and set it up with lib32 (like it is done with Adobe Reader from the mediabuntu rep.), or you set up a 32bit chroot and run it there.