Comment 70 for bug 173966

Alfas, the only java plugin available for 64-bit systems is icedtea-gcjwebplugin. Some applets work, but it's not surprising if the ones you are interested in don't work.

The only option currently available, as far as I know, is to run a hybrid 32bit system. I haven't done that myself, but the 64-bit users forum at ubuntuforums.org would be a good place to start.

-james.