Web browser unplugged

I keep receiving this message after upgrading to Firefox 4.  Does anyone have any suggestions to take care of this?  I have attempted several things, but nothing has helped.  Error message listed below:

( This if for Norton Online Family)

 

Norton Safety Minder plug-in is disconnected or disabled on Katelyn's laptop . To resume monitoring the Internet activities of your children, restart the Web browser or restart the computer. 

smileysad: