Just delete Catalog.LiveSubscribe file from the Symantec LiveSubscribe Directory..... and re-install the application and enjoy uninterrupted norton liveupdate features.
Note: this hack did worked till norton 2005 edition. after that i switched to avg antivirus
Location of Symantec LiveSubscribe Directory:
Win 9X/Me :
C:\WINDOWS\All Users\Application Data\Symantec\LiveSubscribe
Win 2K/XP :
C:\Documents and Settings\All Users\Application Data\Symantec\LiveSubscribe