I've installed the latest Java SDK (1.4.2) and now my path links are broken when I try to load this site:
http://www.fit.qut.edu.au/students/support/oas/

and I get these errors from the Java Console (level 5)

Joined applet thread ... 

Unregistered modality listener Quiting applet ... 

Finding information ... 

Releasing classloader: sun.plugin.ClassLoaderInfo@ee6ad6, refcount=0 

Caching classloader: sun.plugin.ClassLoaderInfo@ee6ad6 

Current classloader cache size: 1 

Done ... 

Registered modality listener Invoking 

JS method: document 

Invoking JS method: URL

Referencing classloader: sun.plugin.ClassLoaderInfo@ee6ad6, refcount=1 

Loading applet ... 

Initializing applet ... 

Starting applet ...

 java.lang.NoSuchMethodError: sun.applet.AppletPanel.changeFrameAppContext(Ljava/awt/Frame;Lsun/awt/AppContext;)V

 	at sun.plugin.viewer.IExplorerPluginObject.appletStateChanged(Unknown Source)

 	at sun.applet.AppletEventMulticaster.appletStateChanged(AppletEventMulticaster.java:32)

 	at sun.applet.AppletPanel.dispatchAppletEvent(AppletPanel.java:232)

 	at sun.applet.AppletPanel.runLoaderAppletPanel.java:531)

 	at sun.applet.AppletPanel.run(AppletPanel.java:292)

	at java.lang.Thread.run(Thread.java:536) 

The error I got through Opera, was that the classpath was broken. Where do I set this?