Welcome to Geeks to go!
is the latest released Java (other than Java 7). I just downloaded Java 7 to see how it performs and so far no issues.
Also check to see if it is enabled in your plug-ins. Go to Tools > Add-ons > Plug-ins
See here-> Using the Java plugin with Firefox
There is also a means to test your Java on that same page under Table of Contents
What version of Firefox do you have installed? I have version 6.0.2 and had an issue with Java not being compatible (along side other Add-ons that are not compatible due to the rapid releases of Firefox) but once I installed Add-on Compatibility Reporter
I've had no issues.....so far!
Edited by DonnaB, 11 September 2011 - 07:11 PM.