Go to tools, and then addons. Click extensions, and DISABLE Java Console 6.0.22 and Java Console 6.0.23, but leave Java Console 3.0.24 ENABLED, and leave the Microsoft .net Framework enabled, along with the Java Quick Starter. Anything other than that can be disabled also, but disabling the java consoles 6.0.22-6.0.23 should do the job.

I only disabled 6.0.22 ONLY and it solved my problem, dont mess with anything else if you can especially 6.0.24

I just found the cause of my problem with the uninstal message. Yahoo toolbar was installed when I installed another unrelated program. When I removed the toolbar the annoying popup disappeared!

I had this problem too, drove me crazy until my son figured out that it was just Firefox (we also use Internet Explorer)...I looked on the help site & immediately saw that others had the same problem. First I did the "DISABLE Java Console 6.0.22" that did not work, so I disabled the Yahoo toolbar (as another user had mentioned). I don't know if it was just the last thing, or both...but the annoying pop up is gone! Yaaay! It only took a few minutes. Firefox Help is great! Thanks to those who post their fix, it does help the rest of us!