Firefox / Intel Mac / Java not working

After installing Firefox 2.0 I go to http://about:plugins and see:

Java Embedding Plugin 0.9.5+g+2

If I check Java version on command line I get:

Legion-Computer:~ tzurita$ java -version
java version "1.5.0_06"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_06-112)
Java HotSpot(TM) Client VM (build 1.5.0_06-64, mixed mode, sharing)

If I go to http://www.java.com/en/download/help/testvm.xml

Ok, Thanks for the responses thus far, to update all, I have done more than the suggestions given. I investigated further and found that Safari, had the same problem. I went to the "Mac Genius Bar" and checked out a vanilla install of OS X 10.4.8. Theirs worked.

By this point I had:
Disabled all plugins that I added
Removed Firefox
Re-added Firefox
Reinstalled Safari
- Tried this by removing Receipts (didn't work)
- Then just mounted the CD cd'ed to the Volume and pulled the safari.pkg out and installed it individual package
Then I backed everything up to an external drive and reinstalled OS X 10.4, patched, restored my home dir and settings (minus plugins)

and.....
Voila, Java was seen by both Safari and Firefox

I get nothing.

I used the MRJPlugin.plugin with Firefox 1.5 and, although I had the same java (1.5) installed it said that I had 1.3 installed. I never knew how to make the plugin see the later version. I also had to open the plugin using Rosetta, for 2.0 I am not opening using Rosetta.

If anybody has a suggestion I would appreciate it. BTW, I have uninstalled and reinstalled. Certain sites do work but I am having a problem with certain sites, the error is:

Your session expired. Please reload this applet by pressing your browsers "Reload" button to restart this session​

From what I know this is normally a cookie session/security problem but I don't believe that is the case here and I am unsure of where to start investigating. If anybody has solved a similar issue, please assist.