A recent Firefox update has started producing warning messages that the Java plugin is unresponsive. This warning can be removed by typing 'about:config' into the Firefox address bar and searching for 'dom.max'.
The three values that are displayed should be set to 0.
We have also made a change on the server which will be picked up by clearing the Java cache. Click Start and type 'configure java'. Click 'Settings', 'Delete Files', select all checkboxes and click 'OK'.
Restart Firefox to apply the changes.