I've been watching the following topic, in the forum:
Tim hasn't updated that topic recently, and I haven't noticed any changed dates for the files in my Firefox plug-in folder:
C:\Documents and Settings\All Users\Application Data\Norton\{0C55C096-0F1D-4F28-AAA2-85EF591126E7}\NAV_17.0.0.136\IPSFFPlgn
I have previously used the MR Tech Firefox extension to force compatibility with Firefox v3.62, so I don't know if Live Update should have updated the files in that folder or not.