Sounds like Firefox is not correctly flipping the switch on the "you've just updated" page.

If you immediately exit Firefox and start it up again (after allowing a few moments to update settings files), does Firefox manage to turn off the message?

If not, hopefully someone has a manual solution to change the setting, or knows what may be causing it.

What is the URL of that page in the location bar ?

Are you referring to some snippet on the about:home page?

Can you attach a screenshot?

• http://en.wikipedia.org/wiki/Screenshot
• https://support.mozilla.org/kb/how-do-i-create-screenshot-my-problem

Use a compressed image type like PNG or JPG to save the screenshot.

If you do not keep changes after a restart then see:

• http://kb.mozillazine.org/Preferences_not_saved