Firefox update page/tab won't go away?

If Firefox update page keeps coming back each time you start Firefox, try the following:
- close firefox
- go to your firefox profile folder
- find prefs.js file, and open it in notepad
If you find an html line at the bottom that starts with a tag "<" and a word like "ScRiPt", just delete that line.

Then save prefs.js
Now start Firefox, then close it, then start it again, and the update page should be gone.