[K12OSN] Java plug-in not working?

[dahopkins at comcast.net]

Can anyone shed light on why the java plug-in does not work in Moz 1.6 with the following site?  I have the latest up-to-date versions of Java (via the Additional software), the symbolic link in the mozilla/plugins directory points to the correct plugins.  Java is enabled in preferences, but ... doesn't work.

A teacher wants to use 

http://illuminations.nctm.org/imath/6-8/PoolTable/pool1.html

Is it the site?

Wits end.
Dave Hopkins