Comment 4 for bug 369562

Oddly enough it appears that firefox by default under Ubuntu is using the OJI plugin.

However, I happened to clear the browser cache and everything now works.
So I guess something bad is being cached.

This didn't just occur on my computer. My colleague had exactly the same issue occur under the latest Kubuntu 9.04 as well - he also resorted to using java 5. I'll get him to try using java6 and clearing the cache out to see if it fixes his problem.