They work in my IE because my IE can load JDK 1.2 classes from the local machine.
That Animator contains a JDK 1.2 class: java.util.ArrayList. This might be the reason you fail. Be sure go to View|Java Console to check Stack Trace of the exception. Be sure. If you cann resolve the problem yourself, you may post the Exception information in the console.
The browser has its own console. It is not MS-DOS. Be sure to check IO console of the browser!